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ADAPTING RIVER BRIDGE INFRASTRUCTURES TO CLIMATE CHANGE
By
Akinola Ifelola, R. Eng, PMP
B.Eng. (Civil), University of Ado Ekiti, Nigeria, 2006
A thesis
presented to Ryerson University
in partial fulfillment of the
requirements for the degree of
Master of Applied Science
in the program of
Civil Engineering
Toronto, Ontario, Canada, 2017
© Akinola Ifelola, 2017
ii
Author's Declaration for Electronic Submission of a Thesis
I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including
any required final revisions, as accepted by my examiners.
I authorize Ryerson University to lend this thesis to other institutions or individuals for the purpose
of scholarly research.
I further authorize Ryerson University to reproduce this thesis by photocopying or by other means,
in total or in part, at the request of other institutions or individuals for the purpose of scholarly
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I understand that my thesis may be made available electronically to the public.
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Adapting River Bridge Infrastructures to Climate Change
Master of Applied Science, 2017
Akinola Ifelola, Civil Engineering, Ryerson University.
Abstract
Climate change forecasts project up to 20% increase in precipitation for southern Ontario based
on several climate change scenarios and models and an unpredictable change an average wind
speed that may range from 5% reduction to 15% increase by the year 2100 compared to 1971 to
2000 reference period. Average annual air temperatures are predicted to increase between 2.5 and
3.7°C by 2050 from baseline average between 1961 and 1990.
This research studied the impact of climate change on bridge infrastructure using the Portage
bridge on the Ottawa river in southern Ontario as a case study. Result shows that increase in
precipitation due to climate change will cause 0.3m/s increase in stream velocity and about 0.85m
increase in water level for a 100-year storm. This increase will result in scour depths at bridge
piers to increase by 0.86 m while bending moments on piers increased by 21 kNm. Shear forces
also increased by 43 kN.
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Acknowledgements
First and foremost, I am extremely grateful to my supervisor, Dr. Lamya Amleh, for her incredible
guidance, expert advice, kindness, patience and great support throughout my graduate study. I
especially thank her for her endless concern and encouragement.
I wish to thank Dr. Luaay Hassein, Assistant program director, First - Year Engineering office for
his encouragement, kind help and useful comments on my research. I would also like to thank my
mum and siblings for their constant encouragement and support. I am most thankful to my wife,
Rachael Ifelola, for her support and contributions. Finally, I also thank my lovely kids. Without
their encouragement and support, I would not have been able to complete my studies.
I am extremely grateful to all these people and I pray that God in his infinite mercies and wisdom
will bring perfection into their lives.
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Dedication
To my Dad,
Late Samuel Olubunmi Ifelola
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Table of Contents
Author's Declaration for Electronic Submission of a Thesis ................................... ii
Abstract ................................................................................................................... iii
Acknowledgements ..................................................................................................iv
Dedication ................................................................................................................. v
Table of Contents .....................................................................................................vi
List of Figures ........................................................................................................... x
List of Tables ......................................................................................................... xiii
List of Appendices..................................................................................................xiv
1 Introduction ....................................................................................................... 1
1.1 Objective and Scope..................................................................................................... 3
1.2 Organization of the Thesis ........................................................................................... 3
2 Literature Review .............................................................................................. 5
2.1 Climate Change ............................................................................................................ 5
2.2 Causes of Climate change ............................................................................................ 5
2.2.1 Natural Causes.................................................................................................. 6
2.2.2 Human Causes .................................................................................................. 6
2.3 Climate Models ............................................................................................................ 8
2.3.1 Regional Climate Models and Dynamic Downscaling ...................................... 8
2.3.2 Canadian Climate Models ................................................................................ 9
2.4 Climate Change Scenarios .......................................................................................... 10
2.4.1 A1 Family ........................................................................................................ 11
2.4.2 A2 Family ........................................................................................................ 11
vii
2.4.3 B1 Family ........................................................................................................ 11
2.4.4 B2 Family ........................................................................................................ 12
2.5 Climate Change in Canada ......................................................................................... 12
2.5.1 Surface air temperature ................................................................................. 12
2.5.2 Precipitation ................................................................................................... 17
2.6 Historical Climate and Projected Changes for Ontario .............................................. 20
2.7 Climate Change and Infrastructure ............................................................................ 22
2.8 Climate Change Impact and Risk Assessment For Civil Infrastructure ...................... 22
2.8.1 Extreme Events Risk Assessment ................................................................... 22
2.8.2 Physical Vulnerability Risk Assessment .......................................................... 23
2.8.3 Functional Vulnerability Risk Assessment ...................................................... 23
2.8.4 Total risk assessment ..................................................................................... 24
2.9 Mechanism of Climate Change Impact on Bridge Infrastructure .............................. 24
2.9.1 Carbonation-Induced Corrosion ..................................................................... 25
2.9.2 Chloride-induced Corrosion ........................................................................... 26
2.9.3 Scouring .......................................................................................................... 28
2.9.4 Extreme weather events ................................................................................ 31
3 Current Research ............................................................................................. 32
3.1 Portage Bridge............................................................................................................ 32
3.2 Methodology for the present study........................................................................... 33
3.3 Hydraulic analysis ....................................................................................................... 33
3.4 Scour Depth Prediction .............................................................................................. 37
3.5 Finite Element Analysis .............................................................................................. 38
3.6 Loading ....................................................................................................................... 40
viii
3.6.1 Dead Loads ..................................................................................................... 40
3.6.2 Hydrostatic Pressure ...................................................................................... 40
3.6.3 Hydrodynamic Pressure ................................................................................. 40
3.6.4 Wind Loads ..................................................................................................... 42
3.6.5 Horizontal drag load ....................................................................................... 42
3.6.6 Vertical Wind Load ......................................................................................... 43
3.6.7 Traffic Loadings .............................................................................................. 44
3.6.8 Design Lane .................................................................................................... 45
3.6.9 Load combinations ......................................................................................... 46
3.7 Analysis....................................................................................................................... 48
4 Results and Discussions .................................................................................. 48
4.1 Hydrological Results and Water Levels For Analyzed 100-Year Storm ...................... 48
4.2 Hydrological Results for 100-Year Storm in Projected Changed Climate .................. 50
4.3 Design scour for 100-year storm ............................................................................... 52
4.4 Scour for 100-year storm in projected climate .......................................................... 53
4.5 Results of bridge elements under normal design loading ......................................... 54
4.5.1 Axial and Shear forces .................................................................................... 54
4.5.2 Bending Moments and Design Requirements ............................................... 56
4.6 Response of Bridge to Loading and Effects of Scouring In Projected Climate........... 61
4.6.1 Axial and shear forces .................................................................................... 61
4.6.2 Bending moments and design requirements ................................................. 62
4.7 Effects of Age and Exposure Conditions and Climate Change Interactions on Concrete
Infrastructures ..................................................................................................................... 67
5 Conclusion and recommendations .................................................................. 68
5.1 Adapting To Climate Change ...................................................................................... 68
ix
5.1.1 Jacketing ......................................................................................................... 68
5.1.2 Scour Protection ............................................................................................. 69
5.2 Future Study ............................................................................................................... 71
Appendices .............................................................................................................. 72
References ............................................................................................................... 90
x
List of Figures
Figure 2.1 Increasing gas concentration in the atmosphere for 2000 years. (Forster et
al., 2007) ......................................................................................................................................... 7
Figure 2.2 Increment in CO2 concentrations in the atmosphere form 1960. (Forster, et
al., 2007) ......................................................................................................................................... 7
Figure 2.3 Change in mean annual temperature in Canada, from 1950 to2007 (Zhang
et al., 2010) ................................................................................................................................... 13
Figure 2.4 Change in mean Spring temperature in Canada from1950 to 2007 (Zhang
et al., 2010) ................................................................................................................................... 14
Figure 2.5 Change in mean Summer temperature in Canada from 1950 to 2007 (Zhang
et al., 2010) ................................................................................................................................... 15
Figure 2.6 Change in mean Fall temperature in Canada from 1950-2007 (Zhang et al.,
2010) ............................................................................................................................................. 15
Figure 2.7 Change in mean Winter temperature in Canada from 1950 to 2007 (Zhang
et al., 2010) ................................................................................................................................... 16
Figure 2.8 Projected change in mean surface air temperature (°C) in Canada in 2041-
2060 relative to 1941-1960 as simulated by CGCM3/T47 in the IPCC SRES A1B
experiment (Environment and Climate Change Canada, 2017) ................................................... 16
Figure 2.9 Projected change in mean surface air temperature (°C) in Canada in 2041-
2060 relative to 1941-1960 as simulated by CGCM3/T47 in the IPCC SRES B1
experiment (Environment and Climate Change Canada, 2017) ................................................... 17
Figure 2.10 Precipitation trends over Canada from 1950 to 2007 (Zhang et al., 2010)
....................................................................................................................................................... 18
Figure 2.11 Projected change in 5-year mean precipitation rate (mm/day) in 2055
relative to 1981-2000 as simulated by CGCM3/T47 in the IPCC SRES A1B experiment
(Environment and Climate Change Canada, 2017) ...................................................................... 19
Figure 2.12 Projected change in 5-year mean precipitation rate (mm/day) in 2055
relative to 1981-2000 as simulated by CGCM3/T47 in the IPCC SRES B1 experiment.
(Environment and Climate Change Canada, 2017) ...................................................................... 20
xi
Figure 2.13 Projected change in 5-year mean precipitation rate (mm/day) in 2055
relative to 1981-2000 as simulated by CGCM3/T47 in the IPCC SRES A2 experiment.
(Environment and Climate Change Canada, 2017) ...................................................................... 20
Figure 2.14 Projected change in average annual temperature in Ontario in 2071 to 2100
compared to 1971 – 2000 using the A2 scenario in the Canadian Coupled Global
Climate model. (Colombo et al, 2007).......................................................................................... 21
Figure 2.15 Typical risk matrix for an extreme event scenario ................................................... 24
Figure 2.16 Corrosion and spalling induced by carbonation (Xiaoming et al. 2010) .................. 26
Figure 2.17 Electrochemical cell at rebar surface induced by chloride penetration
(Xiaoming, et al., 2010) ................................................................................................................ 27
Figure 2.18 Corrosion of steel reinforcement in concrete Structures (Xiaoming et al.,
2010) ............................................................................................................................................. 28
Figure 3.1 Stretch of Ottawa River Showing Portage Bridge and MacDonald-Cartier
Bridge along the Ottawa River ..................................................................................................... 33
Figure 3.2 Digital Elevation map (DEM) of study area showing heights above sea
level. (source: USGS) ................................................................................................................... 34
Figure 3.3 Hydraulic analysis result table for 100-year return period of portage bridge
site ................................................................................................................................................. 35
Figure 3.4 Hydraulic analysis result table for 100-year return period downstream at
portage bridge site ......................................................................................................................... 35
Figure 3.5 Hydraulic analysis result table for 100-year return period plus 20% increase
in discharge upstream at portage bridge site ................................................................................. 36
Figure 3.6 Hydraulic analysis result table for 100-year return period plus 20% increase
in discharge downstream at portage bridge site ............................................................................ 36
Figure 3.7 3D Model of Bridge Analysis section ........................................................................ 39
Figure 3.8 Transverse section of Bridge model ........................................................................... 39
Figure 3.9 Longitudinal view of bridge model. ........................................................................... 39
Figure 3.10 Hydrodynamic pressure on bridge piers ................................................................... 42
Figure 3.11 Idealized horizontal wind pressure on piers ............................................................. 43
Figure 3.12 CL-W loading (CSA,2014) ...................................................................................... 45
Figure 3.13 Cl-W Load Envelope (CSA, 2014) .......................................................................... 45
xii
Figure 4.1 Variations in water level for a 100-year storm event along a stretch of
Ottawa River ................................................................................................................................. 49
Figure 4.2 Water surface levels at the portage bridge site for 100-year storm event .................. 49
Figure 4.3 Variations in velocities along the river reaches .......................................................... 50
Figure 4.4 Variations in water level for a 100-year storm event along a stretch of
Ottawa River for projected climate ............................................................................................... 51
Figure 4.5 Water surface levels at the portage bridge site for 100-year storm event in
projected climate ........................................................................................................................... 51
Figure 4.6 Variations in velocities along the river reaches in projected climate ......................... 52
Figure 4.7 Bridge scour in a 100-year storm ............................................................................... 53
Figure 4.8 Bridge scour for a 100-year storm in projected Climate ............................................ 54
Figure 4.9 Plan of bridge piers arrangement ................................................................................ 54
Figure 4.10 Axial load envelope for pier 7 .................................................................................. 55
Figure 4.11 Shear force envelope for pier 7 ................................................................................ 55
Figure 4.12 Axial load envelope for pier 8 .................................................................................. 55
Figure 4.13 Shear force envelope for pier 8 ................................................................................ 56
Figure 4.14 Bending moment envelope for pier 7. ...................................................................... 56
Figure 4.15 Bending moment envelope for pier 8. ...................................................................... 57
Figure 4.16 Shear force envelope for pier 7 in projected climate ................................................ 62
Figure 4.17 Shear force envelope for pier 8 in projected climate ................................................ 62
Figure 4.18 Bending moment envelope for pier 7 in projected climate ...................................... 63
Figure 4.19 Bending moment envelope for pier 8 in projected climate ...................................... 63
Figure 5.1 Typical cross section of a Pier before and after Jacketing ......................................... 69
xiii
List of Tables
Table 3.1 Unit weights of construction materials (CSA, 2014) .................................................... 40
Table 3.2 Longitudinal drag coefficient (CSA, 2014) ................................................................. 41
Table 3.3 Wind exposure coefficient (CSA S6-14) .................................................................... 44
Table 3.4 Ultimate Load combinations (CSA, 2014) .................................................................. 46
Table 3.5 Live load factors ultimate limit state (CSA,2014) ........................................................ 47
Table 3.6 Permanent loads – Maximum and minimum values of load factors for ULS
(CSA,2014) ................................................................................................................................... 47
Table 4.1- Summary of Bending Moment, Shear Force and reinforcement requirements
....................................................................................................................................................... 67
xiv
List of Appendices
Appendix 1 Output table of hydraulic analysis............................................................................ 72
Appendix 2 Historical discharge data for Ottawa river measured at Carillon (Ottawa
river regulation planning board) ................................................................................................... 74
Appendix 3 Scour calculations input and output for 100- year storm ......................................... 76
Appendix 4 Scour calculations input and output for 100- year storm in projected
climate ........................................................................................................................................... 77
Appendix 5 STAAD Pro input for 100-year design .................................................................... 80
Appendix 6 STAAD Pro input for projected climate .................................................................. 85
1
1 Introduction
River bridges are a critical component of transport networks; therefore, the functionality and
sustainability of river bridges will have a significant effect on the social, economic and physical
development of the society. Infrastructural systems such as bridges often form the core foundation
of many aspects of modern society such as economy and quality of life. In the last century, there
has been a significant change in weather patterns across different zones of the world. This shift is
termed climate change.
The Intergovernmental Panel on Climate Change (IPCC), established by the United Nations (the
world’s most authoritative and recognized body of climate change research) has released several
assessment reports on climate change impact to all zones of the world and made predictions on
how climate change will affect different zones of the world (Intergovernmental Panel on Climate
Change (IPCC, 2007)
According to predictions, climate change will have both detrimental and advantageous effects.
Harmful consequences of climate change which are already being noticed include; sea level rise,
global temperature rise, warming ocean, shrinking ice sheet, declining Arctic ice ocean
acidification and an increase in the frequency of extreme events. Of noteworthy is the increase in
the severity of extreme events apart from their increased frequency. (Intergovernmental Panel on
Climate Change (IPCC, 2007).
One of the strategies to reduce the vulnerability of infrastructures to these changes is to anticipate
and adapt. Before any meaningful adaptation studies and strategies can be implemented for
infrastructures, a clear understanding of the process and impact of climate change is required.
Although a lot of studies have been conducted by researchers generally on climate change, most
of the available studies concentrated on causes, impact and mitigation methods with few studies
done on the adaptation of infrastructures to climate change. Climate change requires a focus on
both slowing climate change, that is, mitigation and adapting to the anticipated impacts of it.
Adaptation, however, has not received as much attention from researchers as much as mitigations.
(Blanco and Alberti, 2009).
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The anticipated impact of climate change which would directly or indirectly affect bridge
infrastructure by an increase in environmental loading and degradation mechanism and rate of
which the materials with which infrastructures are built are, carbonation, chloride penetration,
sulfate attacks, alkali aggregate reactions, precipitation depending on region and increase in storm
surges. (flooding).
There have been studies investigating all these phenomena as discrete occurrences but they have
mostly not been investigated in the context of climate change. These studies did not investigate
the mechanisms of these phenomena and climate change interactions. Yin-hui, et al. (2015)
investigated the effect of water flow pressure on bridge piers. They also studied the scour
associated with water pressure on bridge piers. Cheng, (2012) evaluated the Lateral behavior of
Pile-supported Bridges under scouring conditions. Stewart, Wang, and Nguyen, (2011) however,
investigated Climate change impact and risks of concrete infrastructure deterioration.
In the area of adapting infrastructures to climate change impacts, very few studies have been
carried out and these studies mostly explored strategic management adaptations regarding policy
changes that can be implemented by government agencies and policy makers. Structural
adaptations to the physical infrastructure itself were seldom discussed. Buurman and Babovic,
(2016) discussed the uncertainty in policy making for adaptation to climate change and proposed
several approaches for quantifying and dealing with these uncertainties. Demuzere, et al., (2014)
advocated adaptation on a holistic societal scale through green urban infrastructure development
and averred that green urban infrastructure directly mitigates climate change and adapt the
environment since it directly removes CO2 from the atmosphere via photosynthetic uptake during
the day and releases CO2 at night via respiration.
The big question however is; how do we adapt individual existing infrastructure to climate change
in terms of structural capacity and user’s safety since these structures will be exposed to new
loading in scales and patterns that were non-existence as at the time of design and construction?
How do we also adapt future (yet to be built) infrastructure to climate change as our existing codes
and standards were formulated mostly for past climate? These questions require answers especially
since resources are limited, and all existing infrastructures can’t be rebuilt.
3
1.1 Objective and Scope
The overall goal is to investigate the structural impact of climate change on river bridge
infrastructure using a bridge on the Ottawa River as a case study and to demonstrate the utilization
of the finite element modelling and analysis to investigate the response of the bridge and how the
bridge can be adapted to the structural impacts of climate change. These objectives were achieved
by:
• Apply the HecRas tool to simulate precipitation and water level changes in the future
climate based on selected climate scenarios (HecRas is a computer program that models
the hydraulics of water flow through natural rivers and other channels);
• Simulate historical and future data for the Ottawa river by calibrating the HecRas model
for the river and basin;
• Compare simulation of past scenarios to historical data as a verification for simulations of
future scenarios;
• Apply the HecRas tool to estimate the scour at the base of the bridge pier;
• Apply the tool to estimate the river flow velocity at the location of the bridge;
• Use the finite element software STAAD.PRO to analyze the bridge and investigate the
bridge response to different climate change impact based on the results of scour depth,
water level, and flow velocities;
• Study the effect of climate change on existing structures whose strength has been affected
due to age, use and exposure conditions; and
• Discuss adaptive retrofits to the bridge.
1.2 Organization of the Thesis
Following the introduction, chapter 2 reviews the literature on adapting infrastructure to climate
change. The present body of knowledge and research was explored. Climate change scenarios and
models were looked into and mechanism of climate change impact on bridge infrastructures was
discussed. Material deterioration was discussed in terms of carbonation, chloride penetration,
sulfate attacks and freeze thaw effects. Structural impact of climate change was also discussed.
Factors that will impact the structural integrity of bridges such as flooding and it attendant
hydrostatic and hydrodynamic loading as well as scour effect of flooding on the bridge piers is
discussed.
4
Chapter 3 describes the methodology employed in the current research. In chapter 4, results were
discussed. Axial forces, bending moments and reinforcement requirements for the present climate
and the projected future climate were compared. Chapter discussed conclusions to present study
and looked at recommendations to adapt to climate change and suggested future studies.
5
2 Literature Review
2.1 Climate Change
Climate refers to the average weather conditions prevailing in an area over a long period of time.
In statistical terms, it may be described as the mean and variability of atmospheric variables such
as temperature, precipitation, wind and humidity over a period of time, which can range from
months to centuries. The averaging period for estimating these variables is usually 30 years.
(IPCC, 2014).
However, Rood (2007) averred that climate is much more than weather and atmosphere, He stated
that climate involves contributions of other components of the earth system such as the cryosphere,
ocean, land and their chemical state including the sun and the geological state of the earth which
are significant contributors to climate. He also hinted that the averaging period of 30 years used in
defining climate is dependent on the quality and completeness of observed records which might
be inadequate since extended data record shows an important mode of variabilities longer than 30
years, especially the non-atmospheric components.
“Climate change in IPCC usage refers to a change in the state of the climate that can be identified
(e.g. using statistical tests) by changes in the mean and/or the variability of its properties, and that
persists for an extended period, typically decades or longer.” (IPCC, 2014). Environment and
natural resources Canada defines “climate change as a long-term shift in weather conditions
identified by changes in temperature, precipitation, winds, and other indicators. Climate change
can involve both changes in average conditions and changes in variability, including, for example,
extreme events” (Environment and natural resources Canada, 2015).
2.2 Causes of Climate change
The causes of climate change can best be explained concerning earth energy balance or energy
factors. The earth’s temperature is regulated by outgoing and incoming energy and any factor that
that causes a sustained disruption to the amount of outgoing or incoming energy causes climate
change. Because these factors are external to the earth system, they are referred to as ‘climate
forcers’ to create the impression that they push the climate towards a new state. The new state can
6
be cooler or warmer depending on the climate forces. Causes of climate change can be broadly
categorized into natural and human causes.
2.2.1 Natural Causes
Climate can be affected by natural occurrences that are external to the earth’s climatic system.
These may include changes in the sun’s solar output and volcanic activities
2.2.2 Human Causes
Human causes refer to climate forces that are caused by human activities. The primary cause is
burning of fossil fuels and deforestation as a direct result of logging for timber and clearing for
agriculture and development and results in the release of greenhouse gasses, mainly carbon
dioxide, methane, nitrous oxide and water vapor. Chlorofluorocarbons (CFC) are another major
greenhouse gas contributing to climate change by reacting with and destroying the ozone layer.
The United Nations has acknowledged that present climate change is happening due to human
caused factors (Fung et al., 2011). Figure 2.1 shows the rate of increase in greenhouse gases for
2000 years. It can be deduced that the industrial revolution heralded the sharp increase in a number
of greenhouse gases in the atmosphere. Figure 2.2 also shows the increment in CO2 concentrations
in the atmosphere from 1960.
7
Figure 2.1 Increasing gas concentration in the atmosphere for 2000 years. (Forster et al., 2007)
Figure 2.2 Increment in CO2 concentrations in the atmosphere form 1960. (Forster, et al., 2007)
8
2.3 Climate Models
Climate models are used to study the effect of higher greenhouse gases in the atmosphere based
on increasing amounts of heat that is trapped in the atmosphere. Increased heat affects all aspects
of weather and climate, which includes precipitation, winds, and humidity. Lots of global climate
models have been developed with each one being unique, based on different assumptions and each
one produces different projections of future climate when the same data (scenarios) are provided
as inputs.
The intergovernmental panel on climate change has developed several climate models to analyze
and project what the future climate would likely be. These models development has witnessed
several fine-tuning as technology improves and can be said to be generational. These models are
called Global climate models or General circulation models (GCMs).
A global climate model also called a general circulation model intends to predict climate behavior
by integrating a variety of fluid-dynamical, chemical, or biological equations that are either derived
from physical laws or constructed by empirical means. GCMs have been developed for both the
atmosphere, that is atmospheric GCMs (AGCMs) and the ocean, that is ocean GCMs (OGCMs).
An AGCM and an OGCM can be combined (coupled) together to form an atmosphere-ocean
coupled general circulation model (AOGCM). Other components such as a sea ice model or a land
model are added, and this AOGCM becomes the basis for a full climate model. This allows for
different variations and their varying degrees of response to climate change can be studied.
2.3.1 Regional Climate Models and Dynamic Downscaling
GCMs depict the world climate using a three-dimensional grid over the global space, and the grids
typically have a horizontal resolution of between 250 and 600 km, 10 to 20 vertical layers in the
atmosphere and may have as many as 30 layers in the oceans. This resolution is quite coarse
relative to the scale of exposure units in most impact assessments, therefore only partially fulfilling
criteria of GCM developments. (IPCC, 2017). Many physical processes, such as those related to
clouds occur at smaller scales than the GCMs resolutions and cannot be adequately modeled using
the GCMs. Instead, their known properties are averaged over the larger scale using a technique
9
known as parameterization. This creates a source of uncertainty in GCM based simulations of
future climate.
Also, in the simulation of feedback mechanisms in models relating to water vapor and warming,
clouds and radiation, ocean circulation, ice and snow albedo which occur at scales smaller than the
resolutions of GCMs, results of future climate simulations obtained are marred with a high level
of uncertainties. Because of these, GCMs may simulate quite different responses to the same
forcing because of the way certain processes and feedbacks are modelled. (IPCC, 2017)
In other to solve the problems of uncertainty created by too large resolutions of GCMs, Improved
information on regional climate change can be achieved with the use of different regionalization
techniques, including high-resolution and variable resolution (Jacob, et al., 2007). This results in
Regional Climate Models (RCMs). RCMs are therefore GCMs that has been dynamically
downscaled to produce models of higher resolutions.
Dynamical downscaling is basically the method used to obtain high-resolution climate or climate
change information from coarse-resolution global climate models (GCMs) which does not
adequately capture the effects of local and regional forcing in areas with complex surface
physiography. GCMs are run at a spatial resolution of 150-300 km by 150-300 km and are unable
to resolve important sub-grid scale features such as clouds and topography. Many impacts models
require information at scales of 50 km or less for proper analysis. Hence several downscaling
methods are developed to estimate the smaller-scale information. Dynamical downscaling uses
limited-area, high-resolution model (a regional climate model, or RCM) driven by boundary
conditions from a GCM to derive smaller-scale information which cannot be adequately derived
from global climate models, GCMs, (IPCC, 2017)
2.3.2 Canadian Climate Models
Canada and Canadian climate scientists have not been left out in the development of global climate
models and regional climate models. The Canadian Centre for Climate Modelling and Analysis
(CCCma) has developed a number of climate models. These climate models are used to study
climate change and its variability and to understand the various processes which govern the climate
system. They are also used to make quantitative projections of future long-term climate change
10
given various greenhouse gas and aerosol forcing scenarios and increasingly to make initialized
climate predictions on time scales ranging from seasons to decades. (Environment and Climate
Change Canada, 2017)
Climate models developed by the Canadian Centre for Climate Modelling and Analysis (CCCma)
includes the current and previous models.
2.3.2.1 Current models
Climate models developed and currently in use by Canadian climate reseachers include the
following (Environment and Climate Change Canada, 2017)
CanESM2 The second generation Canadian Earth System Model
CGCM4/CanCM4 The fourth generation and current coupled global climate model
AGCM4/CanAM4 The fourth generation and current atmospheric general circulation model
CGCM3 The third generation coupled global climate model
AGCM3 The third generation atmospheric general circulation model
2.3.2.2 Previous model versions
AGCM1 The first generation atmospheric general circulation model
AGCM2 The second generation atmospheric general circulation model
CGCM1 The first generation coupled global climate model
CGCM2 The second generation coupled global climate model
CRCM The Canadian Regional Climate Model
2.4 Climate Change Scenarios
Future levels of greenhouse gas in itself are not certain and are therefore modeled based on
scenarios, which describe different ways in which the world may develop in the next 100 years.
The Intergovernmental Panel on Climate Change has approved 40 scenarios which may be used
in assessments of climate change and its impacts. The scenario has a different set of assumptions
about future environmental, social and economic conditions. The real amount of greenhouse gas
in the future will depend on variable factors such as global population, human behavior,
11
technological development, carbon source, the behavior of land and water ecosystems. No scenario
is more likely to occur than others, therefore none of the scenarios represent a "best guess" of
future emission. The intergovernmental panel on climate change further grouped these 40 emission
scenarios into four (4) distinct families as described below:
2.4.1 A1 Family
The A1 scenarios are of a more integrated world. The A1 family of scenarios is characterized by
Rapid economic growth. A global population that reaches 9 billions in 2050 and then gradually
declines. The quick spread of new and efficient technologies. A convergent world - income and
way of life converge between regions. Extensive social and cultural interactions worldwide.
There are subsets to the A1 family based on their technological emphasis:
A1FI - An emphasis on fossil-fuels (Fossil Intensive).
A1B - A balanced emphasis on all energy sources.
A1T - Emphasis on non-fossil energy sources (IPCC, 2014).
2.4.2 A2 Family
The A2 scenarios are of a more divided world. The A2 family of scenarios is characterized by:
(a) A world of independently operating, self-reliant nations. (b) Continuously increasing
population and regionally oriented economic development. (IPCC, 2014).
2.4.3 B1 Family
The B1 scenarios are of a world more integrated, and more ecologically friendly. The B1 scenarios
are characterized by:
(a) Rapid economic growth as in A1, but with rapid changes towards a service and information
economy. (b) Rising population to 9 billion in 2050 and then declining as in A1. (c) Reductions in
material intensity and the introduction of clean and resource efficient technologies. (d) Emphasis
on global solutions to economic, social and environmental stability (IPCC, 2014).
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2.4.4 B2 Family
The B2 scenarios are of a world more divided, but more ecologically friendly. The B2 scenarios
are characterized by:
(a) Continuously increasing population, but at a slower rate than in A2 (b) Emphasis on local
rather than global solutions to economic, social and environmental stability (c) Intermediate levels
of economic development and (d) Less rapid and more fragmented technological change than in
A1 and B1. (IPCC, 2014).
2.5 Climate Change in Canada
Canadian scientists have studied climate change over the last two decades. Various federal
government agencies, the provincial government, city councils and industry have sponsored a
series of researches related to climate change, its impacts, mitigation, and adaptations. However,
these studies are scattered around these different agencies and make them somewhat difficult to
access. Examples of these studies include “The impact of climate change on Canadian
municipalities infrastructure,” “Changing weather patterns, uncertainty, and infrastructure risks:
Emerging adaptation requirements”, “Climate change for Ontario: an updated synthesis for policy
makers and planners”, “Adapting infrastructure to climate change in Canadian cities and
communities”, “Cities and communities: The changing climate and increasing vulnerability”,
“Canadian climate trends, 1950 to 2007” and “Temperature and precipitation trends in Canada
during the 20th century”.
These studies were performed to try to understand the observed climate changes, it causes and to
project future trends. Major results of climate trends in Canada and future projections may be
summarized as follows:
2.5.1 Surface air temperature
Zhang et al. (2010) studied temperature trends using data from 210 stations scattered across the
country over a period from 1950 to 2007. These data were rigorously checked and corrected for
known sources of systematic error such as station shifts, changes in procedures used for
observation and excluded stations where there were high urban warming effects. (Zhang, et al.,
13
2010). The daily mean temperature was then computed from the average daily maximum and
minimum temperatures.
From the studies, they concluded that the mean daily temperatures across Canada showed a
significant increase in most regions. Within the time studied, annual mean temperature has
increased by about 1.4oC. (Zhang et al., 2010). This increase differs from zone to zone as shown
in Figure 2.3, the largest increase was observed in northwestern and western region with lowest in
eastern Canada.
Figure 2.3 Change in mean annual temperature in Canada, from 1950 to2007 (Zhang et al.,
2010)
These results agree with results obtained by several other researchers like Bonsal et al. (2000),
Chiotti and Lavender (2008). Historical trends show that the average annual global temperature
warmed by about 0.76°C over the last century (IPCC 2007a:5), but warming in Canada was double
the world average. The average temperature in Canada has increased about 1.2°C in the last 58
years (Environment Canada, 2006). The warming was not uniform across the country. For
example, average annual temperatures increased about 2°C in northwestern British Columbia and
the Kluane region of the Yukon Territory, and by 1.2°C in south-central Canada, but did not change
14
in Atlantic Canada (Environment Canada, 2006). During this period, temperatures across Ontario
increased 0 to 1.4°C (Chiotti and Lavender, 2008).
Seasonal trends have also been studied, change in temperature differs from one season to another
as shown in Figures 2.4 - 2.7. Warming trends are more frequently observed in winter and spring,
with more warming concentrated over western Canada. Some evidence of cooling was observed
in the fall, but these were not significant (Zhang et al. 2010). The only stations showing significant
fall trends are warming over northern Canada. Similarly, in summer the only significant trends are
warming, and these stations tend to be located in southern Canada. Analyses of daily temperature
extremes indicate trends consistent with warming including fewer cold nights, cold days, and frost
days, but more frequent warm nights and warm days. (Vincent and Mekis, 2006). Zhang et al.
(2010) found evidence that increases in atmospheric concentrations of greenhouse gases from
human activities were contributing to temperature increases in Canada.
Figure 2.4 Change in mean Spring temperature in Canada from1950 to 2007 (Zhang et al., 2010)
15
Figure 2.5 Change in mean Summer temperature in Canada from 1950 to 2007 (Zhang et al.,
2010)
Figure 2.6 Change in mean Fall temperature in Canada from 1950-2007 (Zhang et al., 2010)
16
Figure 2.7 Change in mean Winter temperature in Canada from 1950 to 2007 (Zhang et al.,
2010)
Future projections for temperature in Canada have been studied. Figure 2.8 shows the result of
simulations by The Canadian Centre for Climate Modelling and Analysis (CCCma) when they
simulated and projected the likely change in mean surface air temperature (°C) in Canada in 2041-
2060 relative to 1941-1960 as simulated by CGCM3/T47 in the IPCC SRES A1B experiment.
Figure 2.9 shows the projections for the same period while using the IPCC SRES B1 scenario.
Figure 2.8 Projected change in mean surface air temperature (°C) in Canada in 2041-2060
relative to 1941-1960 as simulated by CGCM3/T47 in the IPCC SRES A1B experiment
(Environment and Climate Change Canada, 2017)
17
Figure 2.9 Projected change in mean surface air temperature (°C) in Canada in 2041-2060
relative to 1941-1960 as simulated by CGCM3/T47 in the IPCC SRES B1 experiment
(Environment and Climate Change Canada, 2017)
Both projections show that temperature by the 2050s will increase by an amount of a range 2.5oC
to 4oC relative to the 1950s with northern Canada experiencing the maximum increase.
2.5.2 Precipitation
Zhang et al. (2010) showed that precipitation had increased over Canada since 1950 when he
studied data from 210 different weather stations. The majority of stations with significant trends
showing increases as shown in Figure 2.10. The increasing trend is most obvious over northern
Canada where many stations show significant increases. There is not much evidence of clear
regional patterns in stations showing significant changes in seasonal precipitation except for
significant decreases which tend to be concentrated in the winter season over southwestern and
southeastern Canada. Also, increasing precipitation over the Arctic appears to be occurring in all
seasons except summer. The trend toward increasing precipitation has been accompanied by
increases in extreme daily precipitation amounts during the growing season (Qian et al., 2010).
18
Figure 2.10 Precipitation trends over Canada from 1950 to 2007 (Zhang et al., 2010)
Trends in the annual number of days with measurable precipitation have a similar pattern to trends
in total annual precipitation but with larger numbers of stations showing significant increases and
decreases. This is particularly evident in summer where significant increases in the number of days
with precipitation were observed over most regions of Canada (Zhang et al., 2010). Zhang et al.
(2010) reported that it is difficult to generalize a spatial pattern in precipitation trends apart from
a tendency for stations with significant increases in precipitation amount and the number of days
with precipitation to be located over southern coastal and northern regions of Canada. While it is
not yet clear what is responsible for the precipitation changes in Canada, a recent study found
evidence of anthropogenic influences in observed precipitation increases over Northern
Hemispheric land areas north of 55°N including Canada (Min et al., 2008).
Projections for future precipitation in Canada as simulated by the CCCma shows that annual and
seasonal precipitations are likely to increase across Canada for all the simulated SRES scenarios,
with the greatest increase in northwest Canada.
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Figure 2.11 Projected change in 5-year mean precipitation rate (mm/day) in 2055 relative to
1981-2000 as simulated by CGCM3/T47 in the IPCC SRES A1B experiment (Environment and
Climate Change Canada, 2017)
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Figure 2.12 Projected change in 5-year mean precipitation rate (mm/day) in 2055 relative to
1981-2000 as simulated by CGCM3/T47 in the IPCC SRES B1 experiment. (Environment and
Climate Change Canada, 2017)
Figure 2.13 Projected change in 5-year mean precipitation rate (mm/day) in 2055 relative to
1981-2000 as simulated by CGCM3/T47 in the IPCC SRES A2 experiment. (Environment and
Climate Change Canada, 2017)
2.6 Historical Climate and Projected Changes for Ontario
Scientists have studied Ontario’s historical climate and have projected future climate using
Canadian regional climate models as well as global climate models. Chiotti and Lavander (2008)
projected the seasonal changes in mean temperature in the 2050’s compared with 1961 to 1990
based on a median of seven global climate models (GCMs) and SRES A1F1 to B2. Ontario climate
is changing and will witness an increase in mean temperature and precipitation in the coming
decades. (Chiotti & Lavender, 2008)
Temperature increases in Ontario were significant in several locations during the 20th century. For
example, the average annual temperature near Belleville in Ontario on the north shore of Lake
Ontario has increased by 1.14°C since 1921 (Lemieux et al. 2007). In northwestern Ontario, east
of Sioux Lookout, the average annual temperature has increased by 1.19°C since 1930. Significant
warming in northeastern Ontario has also occurred. Since 1938, the average annual temperature
21
north of Sudbury has increased by 1.14°C, and along the James Bay coastline, the average annual
temperature has increased 1.24°C since 1895 (Lemieux et al. 2007). Warming has been more
significant in winter and spring and is believed to have contributed to changes in evaporation rates,
less snowfall, more rainfall, and shorter periods with ice cover (Lemieux et al. 2005, Vincent and
Mekis 2005). Figure 2.14 shows projected annual temperature difference between 1971 and 2000
and 2071-2100 following the A2 scenario for Ontario.
Figure 2.14 Projected change in average annual temperature in Ontario in 2071 to 2100
compared to 1971 – 2000 using the A2 scenario in the Canadian Coupled Global Climate model.
(Colombo et al, 2007)
Precipitation has also been on the increase in Ontario in the past decades, Colombo et al. (2007)
reported that even though winter season precipitation is on a reducing trend, warm season
precipitation and average annual precipitation will increase by up to 20% by 2071 to 2100
compared to 1971 to 2000 for the investigated scenarios.
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2.7 Climate Change and Infrastructure
Researchers over the years have recognized the impacts of climate change on infrastructures and
emphasized the need to evaluate the severity of the infrastructure vulnerability and impacts.
Research has also shown that threats are posed to both existing and future infrastructures. The
current and potential impacts of climate change on infrastructure include both beneficial and
detrimental effects (Research & Analysis Division Infrastructure Canada, 2006). Flooding is an
example of detrimental effects, which causes scouring and in some cases, total bridge washouts.
(Wright et al, 2012) evaluated the impact of climate change on bridge performance associated with
climate change and submitted that although many bridges are already vulnerable to scour,
incremental vulnerability is caused because of climate change.
With building infrastructures, material deterioration and flooding are of major concern, concrete,
steel and wood that are the main materials for building infrastructure are sensitive to climate
change. More carbon dioxide in the atmosphere is a problem to reinforced concrete whose
deterioration may occur as a direct result of carbonation. Atmospheric humidity will impact steel
buildings in terms of corrosion rate while the wood structures and products will rot in moist
environments. Overall, climate change will cause the rate of material deterioration to be
exacerbated.
2.8 Climate Change Impact and Risk Assessment For Civil
Infrastructure
Before any meaningful discussion can be carried out on climate change adaptation, a risk
assessment framework must be developed. This helps in assessing vulnerabilities and impending
hazards that adaptation measures are implemented as a mitigation strategy. It is imperative to
assess the risk of climate change impact on each particular type of infrastructure. These risks
assessment may be defined or carried out based on:
2.8.1 Extreme Events Risk Assessment
This requires an assessment of extreme events that may occur due to climate change and its
impacts. According to intergovernmental panel on climate change reports, the following extreme
climate changes are expected: drought periods increase, the extreme hot temperature increase in
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intensity and temporal occurrence, the number of days of heat wave increase, extreme precipitation
increase in intensity, the number of days with snowfall decrease. Moreover, extreme events: forest
fires, flooding, ground movements, temporary sea flooding, biodiversity (avifauna corridors
evolutions, algal blooms in waterways), etc., are likely to evolve. (Marie et al, 2016).
A list of these extreme events should be made and scores assigned to them based on intensity and
frequency of occurrence.
2.8.2 Physical Vulnerability Risk Assessment
This is a physical assessment based on factors such as the age of the infrastructure, materials,
expected lifetime, design rules or localization. It is also of importance to consider extreme events
the infrastructure has faced in the past for existing infrastructures. A scoring regime should be
developed for this assessment. Physical vulnerability should consider both ultimate and
serviceability limits of failure of the specific infrastructure.
2.8.3 Functional Vulnerability Risk Assessment
Civil infrastructure supports different types of functionalities, for example, transportation
infrastructure supports crucial functionalities such as rescue services, firemen or police access,
evacuation of persons; accessibility functionalities, such as food and health centers and common
functionalities such as goods and passengers common transport services (Marie et al, 2016)
Functional vulnerability refers to the loss of functionality that may occur in the event of an extreme
weather event. Functional vulnerability risk assessment is the analysis of the expected impacts on
services that would be affected, for example, destruction of a hospital access road may not directly
cause death but the delay in reaching a health facility due to detours may cause death, or permanent
disabilities.
Extreme climate event’s impact on functionalities of transport network will include degradation of
the quality of service, capacity, increase in cost and time and even vehicle deterioration.
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2.8.4 Total risk assessment
The total risk assessment is determined by the combination of risk scores of the extreme events,
functional vulnerabilities, and physical vulnerabilities. This risk level or score forms the baseline
or metrics on which adaptation strategies are developed. Each type of risk assessment should be
carried out using a risk matrix as shown in Figure 2.15. Each extreme event should be analyzed.
The risk for a particular event is the product of the probability of occurrence and the severity.
Immediate adaptation strategies must be developed for events with high-risk values.
Figure 2.15 Typical risk matrix for an extreme event scenario
2.9 Mechanism of Climate Change Impact on Bridge
Infrastructure
Climate change will affect transport infrastructure and bridge infrastructure in particular by
exacerbating the standard bridge deterioration mechanisms, and these include material
deterioration and structural failures due to increased loadings. These mechanisms will include
carbonation, chloride penetration which ultimately leads to corrosion of steel and scouring which
undermines the integrity of the bridge foundation.
Most river bridges are constructed with materials such as steel, concrete and wood either in
combinations as composite as in reinforced and pre-stressed concrete bridges or as stand-alone as
25
in steel and wooden bridges. All these materials react to elements of climate and will be impacted
by change in climate since their designs and construction are based on inputs which includes
climate characteristics such as temperature, relative humidity and atmospheric pollution.
Corrosion, a widespread cause of deterioration in bridges containing steel causes material loss and
if not treated, increasing corrosion damage may lead to reduced safety, premature in-service
failures as well as altered structural behavior and failure modes (Kallias and Imam, 2013).
Exposure design conditions of these structures are directly dependent on climate parameters and a
change in these exposure conditions will cause changes in deterioration process.
2.9.1 Carbonation-Induced Corrosion
Carbonation is a phenomenon, which occurs in concrete as a result of the dissolution of carbon di-
oxide (CO2) in the concrete pore fluid to form carbonic acid (H2CO3). This reacts with calcium
from calcium hydroxide and calcium silicate hydrate present in the concrete to form calcium
carbonate (CaCO3).
CO2 + H2O ↔ H2CO3 (2.1)
H2CO3 + Ca(OH)2 → CaCO3 + 2H2O (2.2)
The presence of Ca(OH)2 in concrete gives it a PH value of about 12.5. The highly alkaline
environment of concrete creates a protective, passivating oxide layer around steel when present in
the concrete protecting the reinforcement from corrosion. Carbonation of concrete reduces a
concrete’s pH to a value less than 9, which weakens, or could even eliminate the steel’s protective
layer and herald the process of corrosion. It should be noted that carbonation gradually propagates
from the concrete surface towards the reinforcement and when carbonation depth equals the
concrete cover, corrosion of the reinforcement starts.
Carbonation depth depends on many parameters such as concrete quality, concrete cover, relative
humidity, ambient carbon dioxide concentration and others. Many researchers have studied the
impact of carbonation and various mathematical models have been developed with the purpose of
predicting carbonation depths. Stewart, et al. (2011) showed that climate change, which is
associated with increased level of carbon di-oxide in the atmosphere and increased atmospheric
temperatures effectively accelerates the deterioration of concretes containing steel reinforcements.
26
Figure 2.16 shows a section of a reinforced concrete structure that is undergoing degradation by
corrosion and spalling induced by carbonation
Figure 2.16 Corrosion and spalling induced by carbonation (Xiaoming et al. 2010)
2.9.2 Chloride-induced Corrosion
Steel bars used as reinforcement in concrete are covered by a thin passive layer of oxide that
protects them from oxygen and water, which causes corrosion and the production of rust when
they get to the steel, as shown in Figure 2.17. This passive layer can only be maintained at an
alkaline pH values i.e. pH>12 or at a chloride ion content less than a corrosion threshold. When
chloride ions penetrate the concrete and then accumulate to a critical level on the surface of steel
reinforcement, the protective layer is destroyed in a process known as de-passivation. (Xiaoming,
et al, 2010). This causes an electrochemical cell to be formed. Figure 2.17 shows the
Electrochemical cell at rebar surface induced by chloride penetration.
27
Figure 2.17 Electrochemical cell at rebar surface induced by chloride penetration (Xiaoming et
al., 2010)
The chemical reactions for chloride-induced corrosion at the steel surface involves the following
reaction as shown by Xiaoming, et al. (2010).
Fe++ + 2Cl– → FeCl2 (2.3)
FeCl2 + 2H2O → Fe(OH)2 + 2HCl (2.4)
The de-passivated area becomes an anode, while the passivated surface becomes a cathode. At the
anode of the cell, the reaction is described by:
Fe → Fe++ + 2e– (2.5)
Fe++ + 2(OH)– → Fe(OH)2 (2.6)
4Fe(OH)2 + 2H2O + O2 → 4Fe(OH)3 (2.7)
and the reaction at the cathode is given by:
4e– + O2 + 2H2O → 4(OH)– (2.8)
During the corrosion process, two major rust and corrosion products are Fe(OH)2 (ferrous
hydroxide) and Fe(OH)3 (ferric hydroxide).
28
Figure 2.18 Corrosion of steel reinforcement in concrete Structures (Xiaoming et al., 2010)
Chlorides induced corrosion depends on three main factors which are diffusion coefficient of
concrete, surface chloride concentration and critical chloride level beyond which corrosion of
reinforcement will be initiated. (Xiaoming, et al. 2010). The coefficient of diffusion depends on
the microstructure of the concrete.
Climate change will hence speed up chloride-induced corrosion as it is associated with increased
carbon dioxide and carbonation which affects the concrete micro structure. Saeki (2002) studied
the effect of carbonation on chloride penetration of concrete and submitted that chloride penetrated
is accelerated in carbonated concrete.
2.9.3 Scouring
Scouring refers to the erosion of bed material around structures such as abutments and piers caused
by water flowing around the structure. It occurs when more sediment material is transported out
of an area than into it. Bridge piers or other obstacles that obstruct the flow and cause a change to
the flow field initiate the scouring process. The material on the bed and banks of a river erodes
when the drag and uplift forces from the flow exceed those of gravity on the bed materials, friction
29
and cohesion. The depth and extent of scour depends on many factors such as the water flow, size
and shape of the obstruction and type of sediment material. Different materials erode at varying
speeds. it will take longer for a cohesive soil to erode than for a loose granular soil due to cohesive
and Van der Waal forces, but the final scour depth can be the same in both types of soils (Chase
and Holnbeck, 2004).
The total scour at a bridge consists of three components; long-term aggradation and degradation,
general scour and local scour. With climate change, increased precipitation intensity and extremes,
which is usually associated with flooding is bound to increase scouring at bridge foundations and
jeopardizing the stability of bridges.
2.9.3.1 Clear-Water and Live Bed Scour
The two different types of sediment transport mechanisms are clear-water and live-bed scour.
Clearwater scour occurs when there is no transportation of sediment from upstream of the bridge
or the sediment being transported remains in suspension and is not deposited into the scour-hole.
Live-bed scour, also known as continuous sediment transport scour, occurs when sediment
material is being transported into the area from upstream during the scour process. The equilibrium
state is dynamic, and the scour depth oscillates non-periodically as bed material is being
transported in and out of the scour hole. The equilibrium state for this type of sediment
transportation is reached faster than for clear-water scour. The scour depth at a certain pier is about
ten percent greater in a clear-water situation compared to a live-bed situation (Chase and Holnbeck,
2004). Clear water scour tends to occur at a slower rate than that of the live-bed scour.
2.9.3.2 Long-Term Aggradation and Degradation
Aggradation and degradation are long-term changes to the elevation of a streambed. Aggradation
means that sediment is brought into the area from upstream and is being deposited at the
downstream. This causes a rise in the bed elevation of the downstream. Degradation refers to
situations when the bed materials are being transported away resulting in a decrease in elevation
of the stream or riverbed. These changes can be either a natural trend of the river or a result of
some man-made modifications of the stream.
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2.9.3.3 General Scour
General scour is when the streambed lowers due to changes in the water flow caused by flow
through a contraction or around a bend. This type of scour can lead to various scour depths at
different parts along the cross-section or it can result in to a uniform lowering of the streambed.
The difference between general scour and long-term degradation is that the general scour can be a
cyclic process. Contraction scour occurs when the available flow area decreases. This happens at
a bridge if the piers are placed in the river or the abutments are placed at the bank lines or in the
river resulting in a decrease in flow area and causes an increase in flow velocity. The increased
velocity causes an increase of erosive forces and the streambed starts to erode. As the bed elevation
is lowered the available flow area increases and the flow velocity and scour decrease until
equilibrium state is reached.
2.9.3.4 Local Scour
Local scour around bridge piers is the result of the acceleration of the flow and formation of
vortices around the piers. As the flow is interrupted a strong pressure field decreasing with the
depth is formed in front of the obstruction. If the pressure field is strong enough, it causes a three-
dimensional separation of the boundary layer. It drives the approaching flow downwards, and a
recirculating primary vortex is formed on the upstream side of the pier. As the flow passes through
the bridge, the vortices wrap around the sides of the piers in the shape of a horseshoe and continue
downstream. This is called a horseshoe vortex
The primary vortex system in front of the pier is the main scour force, and it removes bed material
from the base of the pier. Since the rate at which material is carried away from the area is greater
than the transport rate into it, a scour hole is formed around the pier. As the scour hole gets deeper
the strength of the vortices at the base of the pier decrease and eventually a state of equilibrium is
reached. For a clear-water situation that happens when the shear stress from the vortices equals the
critical stress for the sediment particles, and no more bed material is scoured. For a live-bed
situation, equilibrium is reached when the amount of sediment inflow equals the amount of outflow
from the scour hole. In that situation, the scour depth fluctuates, while the average depth remains
constant.
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The horseshoe vortices act mainly on the upstream face and the sides of a pier, whereas on the
downstream side of the pier another type of vortices dominate, called wake vortices. They are
formed along the surface of the pier, then detached from both sides and continue downstream The
wake vortices together with the accelerated side flow and the upward flow behind the pier causes
the downstream scouring. The pier itself generates the wake vortices, and their size and strength
depend mainly on the velocity of the flow and the pier size and shape. The strength of a wake
vortex declines rapidly downstream of a pier and therefore there is often a deposit of material
downstream of piers (Chase and Holnbeck, 2004).
2.9.4 Extreme weather events
The focus of earlier climate model studies of global warming was mainly on changes in mean
climate. It has been only since the early 1990s that climate models have started to be analyzed to
study possible changes of future weather and climate extremes (Meehl et al., 2000).
There is also clear evidence of changes in extremes of precipitation. For the contiguous United
States and Canada. Kunkel et al. (2003) and Groisman et al. (2008) find statistically significant
increases in heavy (upper 5%) and very heavy (upper 1%) precipitation by 14% and 20%,
respectively. Much of this increase occurred during the last three decades of the century especially
over the eastern parts of United States. Groisman et al. (2008) showed that even as the top 0.3%
of heavy rains has increased by 27% from 1967 to 2006, so have dry spells increased in most
places. Also, there is evidence for Europe and the United States that the relative increase in
precipitation extremes is larger than the increase in mean precipitation, and this is manifested as
an increasing contribution of heavy events to total precipitation (Alexander et al., 2006). Globally-
averaged over the land area with sufficient data, the percentage contribution to total annual
precipitation from very wet days (upper 5%) has increased in the past 50 years even in places
where mean precipitation amounts are not increasing (Kunkel et al. (1999).
Flooding records are often confounded by changes in land use and increasing human settlement in
flood plains. Nevertheless, great floods have been found to be increasing in the twentieth century
(Paasche and Storen, 2014).
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3 Current Research
To investigate the structural impact of climate change on river bridge infrastructure, a bridge on
the Ottawa river was used as a case study to demonstrate the utilization of the finite element
modelling and analysis to investigate the response of the bridge and how the bridge can be adapted
to the structural impacts of climate change.
3.1 Portage Bridge
The Portage bridge is a bridge on the Ottawa River. It crosses the river downstream of the
Chaudiere bridge. It is the link between Laurier street and Alexander-Tache boulevard. The bridge
was completed and opened in 1973 by the National Capital Commission. The Portage bridge is
160 meters long.
The Ottawa river is a river in the Canadian provinces of Ontario and Quebec. For most of its length,
it defines the border between the two provinces. It is a major tributary of the St. Lawrence River.
The river rises at Lake Capimitchigama, in the Laurentian Mountains of central Quebec, and flows
west to Lake Timiskaming. From there its route has been used to define the interprovincial border
with Ontario. From Lake Timiskaming, the river flows southeast to Ottawa and Gatineau, where
it tumbles over the Chaudière Falls and further takes in the Rideau and Gatineau rivers.
The Ottawa River drains into the Lake of Two Mountains and the St. Lawrence River at Montreal.
The river is 1,271 kilometers long. it drains an area of 146,300 square kilometers, 65 percent in
Quebec and the rest in Ontario, with a mean discharge of 1,950 cubic meters per second. The
average annual mean water-flow measured at Carillon dam, near the Lake of Two Mountains, is
1,939 cubic meters per second with average annual extremes of 749 to 5,351 cubic meters per
second. Record historic levels since 1964 are a low of 529 cubic meters per second in 2005 and a
high of 8,190 cubic meters per second. Figure 3.1 shows a stretch of Ottawa river showing portage
bridge.
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Figure 3.1 Stretch of Ottawa River Showing Portage Bridge and MacDonald-Cartier Bridge
3.2 Methodology for the present study
Precipitation and flood level historical data for the study area was obtained from the Ottawa River
Regulation Planning Board, data included the historical water levels and discharges along the
Ottawa river at Lake Timiskaming, Mattawa, Pembroke, Lake Coulonge, Arnprior, Britannia,
Hull, Grenville and Carillon. These flood data were used to determine the 1:100- year flood
discharge of the basin. A 20% increase in discharge was determined to simulate the likely increase
in flood levels due to climate change as projected for the basin. These data were used for hydraulic
analysis to derive the channel velocity, inundation depths and scour depths around bridge piers in
a flood event. The flood data is included in Appendix 2.
Results of the hydraulic analysis, which were Stream Velocity (m/s), Scour depth (m) and flood
levels (inundation depths) (m) were then used in a structural model alongside other structural loads
to determine the response of bridges along the basin.
3.3 Hydraulic analysis
Digital elevation models (DEM) for the study area which were derived from LIDAR data was
obtained from the United States Geological Survey (USGS) for the purposes of this study. The
Portage Bridge
34
DEMs were processed into Triangulated irregular network maps (TIN) and cross sections, stream
center line, river bank and over banks were digitized using ArcGIS software version 10.4.1. The
purpose of these is to create a dataset compatible with HEC-RAS which was used for the hydraulic
analysis and scour prediction.
Figure 3.2 Digital Elevation map (DEM) of study area showing heights above sea level. (source:
USGS)
The HEC-RAS (version 5.0.3) is a software developed by the US Army Corps of Engineers
(USACE, 2016). It uses the backwater calculation procedure as HEC-2 (USACE, 1990) which has
been the industry standard in flood water hydraulic modelling but with improved data processing
and graphical capabilities. (Ferdous, et al. 2014). A steady-state hydraulic model was then
developed in HEC-RAS using the data set and cross sections generated in ArcGIS as imported
inputs. In total, twenty-one cross sections and the bridge site was included in the analysis. The
final model was run with the estimated flood discharges for a 100-year storm, which is the standard
used in bridge designs. Additional runs were conducted for 100-year plus 20% to simulate the
projected increase in precipitation due to climate change at the portage bridge site on the Ottawa
River. Figure 3.3 and
Figure 3.4 show hydraulic analysis output for the basin for a 100-year storm at upstream and
downstream cross-section of the bridge respectively while Figure 3.5 and Figure 3.6 show the
35
hydraulic analysis results for 100-year 100 plus 20% increase in discharge due to climate change
respectively.
Figure 3.3 Hydraulic analysis result table for 100-year return period of portage bridge site
Figure 3.4 Hydraulic analysis result table for 100-year return period downstream at portage
bridge site
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Figure 3.5 Hydraulic analysis result table for 100-year return period plus 20% increase in
discharge upstream at portage bridge site
Figure 3.6 Hydraulic analysis result table for 100-year return period plus 20% increase in
discharge downstream at portage bridge site
37
The stream flow velocity at any point in time at any position is calculated by HEC-RAS using the
manning’s equation:
Q=VA=(1/n) AR2/3√S (3.1)
Where:
Q = Flow Rate, (m3/s)
v = Velocity, (m/s)
A = Flow Area, (m2)
n = Manning’s Roughness Coefficient
R = Hydraulic Radius, (m)
S = Channel Slope, (m/m)
3.4 Scour Depth Prediction
Several research studies have been carried out with the aim of predicting scour, and various
equations have been developed. Khwairakpam et al. (2012) provided examples of such studies to
include Laursen and Toch (1956), Liu et al. (1961), Shen et al. (1969), Breusers et al. (1977), Jain
and Fischer (1984), Melville and Sutherland (1988), Froehlich (1989), Melville (1992), Abed and
Gasser (1993), Richardson and Richardson (1994), Lim (1997) and Heza et al. (2007).
Most of these empirical equations were based on results of laboratory and field data, and they
differ from one another based on the factors and parameters considered in constructing the scour
model, laboratory or field conditions. Out of these equations, the most commonly used pier scour
equations in the is the Colorado State University scour equation (Khwairakpam et al. 2012).
The scour depth was calculated using HEC -RAS. HEC RAS scour prediction model is based on
the scour equation developed by Colorado State University and recommended by the U.S.
Department of Transportation’s Hydraulic Engineering Circular No. 18 (HEC-18), Federal
Highway Administration (1993), which is expressed as follows:
ds = 2.0yK1K2K 3 K 4 b 0.65F 0.43 (3.2)
where ds = scour depth,
38
y = flow depth at upstream of pier
K1, K2, K3 K 4 = correction factors for pier nose shape, angle of attack, bed conditions and
armouring respectively,
b = pier width,
F = Froude number.
It is recommended in the HEC-18 that the limiting value of ds/y is 2.4 for F = 0.8 and 3.0 for F
greater than 0.8. The scour equation was developed from laboratory data and was recommended
for both live-bed and clear-water conditions (USACE, 1990).
3.5 Finite Element Analysis
A finite element model of a bridge at the site of Portage bridge was developed and calibrated using
the finite element analysis software STAAD Pro to simulate the existing bridge circumstances and
design. The bridge was analyzed for loads based on the Canadian highway bridge design code.
(CHBDC). The model conforms to the initial bridge geometry design to resist a 100-year flood,
wind load and other antecedent loads such as dead and live loads.
The model was constructed to study the effect of increased scour depth and increased flood load
on the existing bridge. The bridge model was idealized as a beam bridge which consists of a 250
mm reinforced concrete deck supported by 8 reinforced concrete girders spanning continuously
over eight 20 m spans. The transverse width of the deck is 17 m and carries 4 lanes of highway
each 3.5 m wide. On each extreme side is a shoulder of 1.5m wide each. The center to center
spacing between girders is 2.143m with deck overhangs of 1.0m on either side. The girders are
supported on beams of 800 mm by 1000 mm depths. Each beam is in turn supported on two 800mm
diameter piers, and each has a length of 14.78m from the top of the pile cap. These piers are
assumed to be fixed at the base. The girders at the two end spans were supported on roller supports
to simulate the support found between the girders and abutment interface at end spans.
Figure 3.7 shows a 3d model of the bridge while
Figure 3.8 and Figure 3.9 shows the transverse and longitudinal sections respectively.
More runs of the models were carried out to study the response when the 100-year flood has
increased by 20%. The results were then analyzed to determine their response to the increased
flood and wind load. It is desired to check the capacity of these bridges to resist the added loads
39
and hence determine their safety. The STAAD.pro code input of finite element analysis is included
in appendices 4 and 5.
Figure 3.7 3D Model of Bridge Analysis section
Figure 3.8 Transverse section of Bridge model
Figure 3.9 Longitudinal view of bridge model.
40
3.6 Loading
3.6.1 Dead Loads
Dead loads included the weight of all components of the structure and fixtures attached to the
bridge, including wearing surface. Unit material weights as specified in Table 3.4 of Canadian
Highway Bridge Design Code and reproduced as Table 3.1 in this report was used in calculating
dead loads. The weight of water was considered as a dead load in line with the specifications of
the CHBDC.
Table 3.1 Unit weights of construction materials (CSA, 2014)
Material Unit weight, kN/m3
Bituminous wearing surface 23.5
Reinforced concrete 24
Steel 77
Fresh water 9.8
3.6.2 Hydrostatic Pressure
Static water pressure is assumed to act perpendicular to the surface that is retaining the water (The
piers). The pressure of water at a specific point is calculated as the product of the height of water
above that point and the density of water.
Hydrostatic pressure = ρgh
where ρ = density;
g = acceleration due to gravity and
h= height of liquid.
3.6.3 Hydrodynamic Pressure
The hydrodynamic pressure, also called the longitudinal effect is the load due to flowing water
acting longitudinally on an element and is taken as CDρAv2/2, where the longitudinal drag
coefficient, CD, is as specified in Table 3.11. of CHBDC and reproduced as
41
Table 3.2 in this report. Other parameters of the hydrodynamic effect are defined as follows:
ρ = density
L = length of a pier along the longitudinal axis
A = Area obstructing flow
V = Velocity of flow.
Table 3.2 Longitudinal drag coefficient (CSA, 2014)
Upstream shape of pier Longitudinal drag
coefficient, CD
Semicircular nosed 0.7
Square ended 1.4
Wedged nosed < 90 0.8
Pier with debris lodged 1.4
Two profiles were investigated based on stream flow velocity for a 100-year flood and 100-year
flood and 20% increase in discharge and a 100-year flood. The scour depth at each event was
used to determine the section where the hydrodynamic pressure acts on. Figure 3.10 shows the
idealized hydrodynamic pressure on piers. The two profiles are:
Profile 1- 100-year return flood
Flow velocity = 3.8 m/s
Submerged height = 10.5 m
Width of pier = 0.8 m
Pressure = 1000∗11.12∗0.8∗0.7∗3.82
2= 44.96𝑘𝑁
Pressure over submerged height = 4.28 kN/m
Profile 2- 100-year return flood plus 20% increase in precipitation
Flow velocity = 3.99 m/s
Submerged height = 12.52 m
Width of pier = 0.8 m
Pressure = 1000∗12.52∗0.8∗0.7∗3.992
2= 55.8𝑘𝑁
42
Pressure over submerged height = 4.46 KN/m
Figure 3.10 Hydrodynamic pressure on bridge piers
3.6.4 Wind Loads
Wind loads were divided into two components as horizontal drag load and vertical load acting
simultaneously as specified by CHBDC.
3.6.5 Horizontal drag load
A horizontal wind load of Fh = qCeCgCh was applied to the bridge structure. Fh is horizontal wind
load, q is Reference wind pressure, Ce is exposure coefficient and Cg is the gust effect coefficient.
Ce and q are as specified in Tables in the CHBDC, Ce is reproduced here in
Table 3.3. Cg = 2.5, Ch = 2.0 and the reference wind pressure for study area (Ottawa) is 460 Pa.
Fh = qCeCgCh
43
=0.46 x 1.2 x 2.5 x 2.0 = 2.76KN/m2
Diameter of pier = 0.8m
Fh = 2.76 x 0.8 = 2.208 kN/m
The horizontal wind acts on the exposed portion of the bridge. Portions submerged in water do not
experience the wind. Figure 3.11 shows the idealized wind pressure on the bridge piers.
Figure 3.11 Idealized horizontal wind pressure on piers
3.6.6 Vertical Wind Load
A vertical wind is applied as a uniform distributed load over the whole surface of the bridge deck
Fv = qCeCgCv, where Fv is vertical wind load, q is Reference wind pressure, Ce is exposure
coefficient and Cg is the gust effect coefficient. Ce is as specified in Tables in the CHBDC and
reproduced here in
Table 3.3 and Cg = 2.5 and Cv = 1.0.
An additional wind load of same value as Fv is applied as an equivalent line load at the windward
quarter point of the transverse width of the deck in accordance with CHBDC
Fv = qCeCgCv
q= 0.46 kN/m2 (Ottawa average wind speed. Source CHBDC)
44
Fv = 1.2 x 2.5 x 1 x 0.46 =1.38 kN/m
Table 3.3 Wind exposure coefficient (CSA S6-14)
Height above ground of the top
of the superstructure, H (m)
Wind exposure
coefficient, Ce
0 – 10 1
Over 10 -16 1.1
Over 16 – 25 1.2
Over 25 – 37 1.3
Over 37 – 54 1.4
Over 54 – 76 1.5
Over 76 - 105 1.6
3.6.7 Traffic Loadings
3.6.7.1 Truck Loads
In this study, the bridge deck was loaded with the Canadian CL-W truck. A CL-W truck is the
idealized five-axle vehicle as shown in Figure 3.12. Load values, wheel placement, and the lengths
have been calibrated for a 625 kN truck, which is the legal limit in Canada. This truck is
encompassed in a 3 x 3 m clearance envelope with 1.8 m wheel to wheel spacing as shown in
Figure 3.13. The CL-W truck is positioned longitudinally and transversely within a design lane at
the location and in the direction, that produces maximum load effect for the design of each bridge
element.
3.6.7.2 Lane Loads
The CL-W lane load consists of a CL-W truck load with each axle reduced to 80% of the values
given in Figure 6 superimposed with a 9 kN/m lane load applied over an area 3 m wide. As per
Code specification. lane loads should not be applied where it reduces the overall load effects, lane
loads were not applied in this model. Because girders are continuous over supports, application of
the lane load over the entire superstructure would result in lower maximum positive bending
moments at mid-spans.
45
3.6.8 Design Lane
This refers to a longitudinal strip that is a fraction of the deck width and within which a truck or
lane load is placed for the purpose of design or evaluation. This model consists of 4 design lanes
each 3m in width. The code specifies that when multiple lanes are loaded on a highway bridge, a
load reduction factor should be applied to account for the probability of all lanes not being loaded
at the same time.
Figure 3.12 CL-W loading (CSA,2014)
Figure 3.13 Cl-W Load Envelope (CSA, 2014)
46
3.6.9 Load combinations
Nine ultimate load combinations were investigated as per CHBDC specifications to determine the
governing load case for design. Table 3.4 below shows the load combinations.
Table 3.4 Ultimate Load combinations (CSA, 2014)
Ultimate limit states
Loads D E P L K W V S EQ F A H
ULS Combination 1 αD αE αP 1.7 0 0 0 0 0 0 0 0
ULS Combination 2 αD αE αP 1.7 1.15 0 0 0 0 0 0 0
ULS Combination 3 αD αE αP 1.7 1 0.45 0.45 0 0 0 0 0
ULS Combination 4 αD αE αP 0 1.25 1.4 0 0 0 0 0 0
ULS Combination 5 αD αE αP 0 0 0 0 0 1 0 0 0
ULS Combination 6 αD αE αP 0 0 0 0 0 0 1.3 0 0
ULS Combination 7 αD αE αP 0 0 0.75 0 0 0 0 1.3 0
ULS Combination 8 αD αE αP 0 0 0 0 0 0 0 0 1
ULS Combination 9 1.35 αE αP 0 0 0 0 0 0 0 0 0
Table 3.4 legend:
A = ice accretion load;
D = dead load;
E = loads due to earth pressure and hydrostatic pressure, including surcharges but excluding dead
load;
EQ = earthquake load;
F = loads due to stream pressure and ice forces or to debris torrents;
H = collision load arising from highway vehicles or vessels;
K = all strains, deformations, and displacements and their effects, including the effects of their
restraint and the effects of friction or stiffness in bearings, also, strains and deformations include
strains and deformations due to temperature change and temperature differential, concrete
shrinkage, differential shrinkage, and creep, but not elastic strains;
L = live load (including the dynamic load allowance, when applicable), including barrier loads; P
= secondary pre-stress effects;
47
S = load due to differential settlement and/or movement of the foundation;
V = wind load on traffic; and
W = wind load on structure
Table 3.5 shows the live load factors for the ultimate limit states while
Table 3.6 shows maximum and minimum values of load factors for ultimate limit state.
Table 3.5 Live load factors ultimate limit state (CSA,2014)
Table 3.6 Permanent loads – Maximum and minimum values of load factors for ULS
(CSA,2014)
48
3.7 Analysis
The bridge model was developed using STAAD Pro finite element analysis and design software
and calibrated with all the appropriate loads. A moving load case was defined and used to generate
the maximum responses (i.e. the location of the CLW-625 loading or lane loading on this bridge
that will generate the maximum responses) on the bridge elements. The maximum response was
combined with other live and dead loads described earlier.
4 Results and Discussions
4.1 Hydrological Results and Water Levels for Analyzed 100-
Year Storm
The water surface levels for the analyzed 5 kilometers stretch of the Ottawa river ranges between
44.54 m and 51.06 m. The water surface level at the cross section of the bridge location was 47.89
m. Critical flow at bridge section occurs at 47.67 m while the total energy line lies at 49.82 m. This
water level is in agreement with the historical water level as measured during an occurrence of the
100-year storm event measured at the Hull station in 1976 and given as 44.74 m.
Figure 4.1 shows the water level and other hydrologic parameters for the river stretch. The water
surface level for the 100-year storm event is labeled PF1. while Figure 4.2 shows the water surface
levels at the portage bridge site.
The result of water levels for the 100-year storm corresponds with measured water levels when a
100-year storm occurred in 1974. The correspondence of these results of the analysis with
measured historical data gives credibility to the calibration of the model.
Chanel flow velocities for the 100-year storm event along the stretch of the river ranges from 1.39
m/s to 4.03 m/s. The velocity just upstream of the bridge is 3.8 m/s while the velocity of flow just
downstream of the bridge is 4.03 m/s. The variation in the velocities is due to changes in profile
along sections of the river. The discharge at any point along the river reach is related to the velocity
of flow and the wetted area by the relationship Q = VA, where A is the wetted area and V is the
49
velocity of flow. The full output table for the hydraulic analysis is shown in Appendix 1. Figure
4.3 shows the variation in velocities along the river reaches.
Figure 4.1 Variations in water level for a 100-year storm event along a stretch of Ottawa River
Figure 4.2 Water surface levels at the portage bridge site for 100-year storm event
50
Figure 4.3 Variations in velocities along the river reaches
4.2 Hydrological Results for 100-Year Storm in Projected
Changed Climate
For a projected climate with a 20% increase in 100-year storm discharge, the water surface levels
for the analyzed 5 kilometer stretch of the Ottawa river ranges between 45.13 m and 51.88 m. This
translate to about 1m increase in average water levels. The water surface level at the cross section
of the bridge location was 48.34 m. Critical flow at bridge section occurs at 48.19 m while the total
energy line lies at 50.63 m. Figure 4.4 shows the water level and other hydrologic parameters for
the river stretch. The water surface level for the 100-year storm event in the projected climate is
labeled PF3. while
Figure 4.5 shows the water surface levels at the portage bridge site.
Channel flow velocities for the 100-year storm event along the stretch of the river ranges from
1.47 m/s to 4.29 m/s. The velocity just upstream of the bridge is 3.99 m/s while velocity of flow
just downstream of bridge is 4.29 m/s. The full output table for the hydraulic analysis is shown in
Appendix 1. Figure 4.6 shows the variations in velocities along the river reaches.
51
Figure 4.4 Variations in water level for a 100-year storm event along a stretch of Ottawa River
for projected climate
Figure 4.5 Water surface levels at the portage bridge site for 100-year storm event in projected
climate
52
Figure 4.6 Variations in velocities along the river reaches in projected climate
4.3 Design scour for 100-year storm
The scour depths at the base of the bridge piers were computed using the Colorado state university
equation (CSU) for live bed scour as recommended in the HEC-18. The piers design scour
consisted of a combination of pier scours and contraction scour that is on an elevation of 36.68m
as shown in Figure 4.7. The total scour depth computed from the difference between the ground
elevation, and the total scour elevation is 6.32 m. A complete description of scour calculations
input and output for 100- year storm is included in Appendix 2. The height of the deck was 51.6
m while the water surface stood at 47.18 m. The total depth of water is the difference between the
water surface and the sour elevation which was 10.5 m.
53
Figure 4.7 Bridge scour in a 100-year storm
4.4 Scour for 100-year storm in projected climate
Again, for the projected climate where the 100-year storm discharge has increased by 20%, the
scour depths at the base of the bridge piers was computed using the CSU equation for live bed
scour as recommended in the HEC-18. The piers design scour consisted of a combination of pier
scours and contraction scour that is on an elevation of 35.82 m in the channel as shown in Figure
4.8. The total scour depth computed from the difference between the ground elevation and the total
scour elevation is 7.18 m. A complete description of scour calculations input and output is provided
in Appendix 3. Diagram showing scour depths in projected climate is shown in Figure 4.8.
54
Figure 4.8 Bridge scour for a 100-year storm in projected Climate
4.5 Results of bridge elements under normal design loading
Highway and river bridges are usually analyzed and designed for a lifespan of 100 years. For the
present study, the response of the bridge elements, that is, beams, girders and piers to loading was
analyzed. The results of two main piers that were found to be critical are discussed here.
4.5.1 Axial and Shear forces
Figure 4.9 shows the arrangement of the piers on the bridge. The piers are numbered 1 to 14, after
analysis, piers 7 and 8 were critical as they were exposed to the largest forces. The maximum axial
force on pier 7 was controlled by ultimate load combination 3 (Table 3.4).
Figure 4.9 Plan of bridge piers arrangement
55
The maximum axial load on pier 7 is 4483 kN, these load combinations include the dead load,
hydrodynamic load and wind load in addition to the vehicle loads. The maximum shear force is
106 kN at the top of the pier. Figure 4.10 and Figure 4.11 shows the axial force and shear force
envelopes diagrams for pier 7.
Figure 4.10 Axial load envelope for pier 7
Figure 4.11 Shear force envelope for pier 7
For pier 8, the maximum axial load and shear force was 4482 kN and 104 kN as shown in Figure
4.12 and Figure 4.13, respectively.
Figure 4.12 Axial load envelope for pier 8
56
Figure 4.13 Shear force envelope for pier 8
4.5.2 Bending Moments and Design Requirements
Lateral forces and load eccentricity induced bending moments in the pier. The maximum bending
moment in pier 7 is 1021 kNm. Figure 4.14 shows the bending moment envelope for pier 7.
Figure 4.14 Bending moment envelope for pier 7.
For pier 8, the maximum bending moment in the pier is 1018KNm as shown in the bending
moment envelope in Figure 4.15.
57
Figure 4.15 Bending moment envelope for pier 8.
The bridge piers were designed according to the Canadian highway bridge design design code.
(CSA,2014) .
Material property for piers
Concrete strength fc' = 30.0 MPa
Concrete Density = 2400 kg/m3
Aggregate size =20 mm
Cover = 40 mm
Exposure Condition Exterior
Steel yield strength fy = 400 MPa
Modulus = 200000 MPa
Pier 8 - CSA-S6 Design Requirements
Section Diameter = 800 mm
Story height = 14.8 m
Circular Section: Diameter = 800 mm
Pier 7 - CSA-S6 Main Reinforcement
Axial Load = -4482.42 kN
Major axis Moment M, end 1 = 1017.53 kNm
end 2 = -510.47 kNm
58
Minor axis moment M, end 1 = -22.77 kNm,
end 2 = 11.34 kNm
Cm = 0.40
∂s = 1.00
Cm = 0.40
∂s = 1.00
Where:
Cm = factor relating actual moment diagram to an equivalent uniform moment diagram
∂s = Moment magnification factor accounting for second-order effects of vertical load acting on a
structure in a laterally displaced configuration
Area of steel provided = 6900 mm2
Axial compression capacity = -4482.42 kN
Resultant moment capacity Mz = -1021.19 kNm
Actual distance between bars = 73 mm
Pier 8 - CSA-S6 Shear Reinforcement
Actual spacing of ties = 300 mm
Major Axis:
Design shear force Vf = 104.02 kN
Shear resisted by concrete:
Vc = Φcλβ√fc'bwdv (4.1)
= 0.65 x 1.00 x 0.297 x √30.00 x 800.00 x 576.00 = 486.75 kN
Shear resisted by steel:
Vs =𝜙𝑠𝐴𝑣𝑓𝑦𝑡𝑑𝑣𝑐𝑜𝑡𝜃
𝑠 (4.2)
= 0.85 x 0.67 x 400.00 x 576.00 x 1.69 = 220.55 kN
Maximum shear capacity
Vr,max = 0.25Φc fc’bwdv (4.3)
= 0.25 x 0.65 x 30.00 x 800.00 x 576.00 = 2246.40 kN
Vr = 486.75 + 220.55 = 707.30 kN
Vr > Vf = OK
Actual area of shear reinforcement (2-10M) = 200 mm2
59
Maximum spacing of ties = 310 mm
Minor Axis:
Design shear force Vf = 22.12 kN
Shear resisted by concrete:
Vc = Φcλβ√fc'bwdv (4.1)
= 0.65 x 1.00 x 0.297 x √30.00 x 800.00 x 576.00 = 486.75 kN
Shear resisted by steel
Vs =𝜙𝑠𝐴𝑣𝑓𝑦𝑡𝑑𝑣𝑐𝑜𝑡𝜃
𝑠 (4.2)
= 0.85 x 0.67 x 400.00 x 576.00 x 1.69 = 220.55 kN
Maximum shear capacity
Vr,max = 0.25Φc fc'bwdv (4.3)
= 0.25 x 0.65 x 30.00 x 800.00 x 576.00 = 2246.40 kN
Vr = 486.75 + 220.55 = 707.30 kN
Vr > Vf = OK
Actual area of shear reinforcement (2-10M) = 200 mm2
Maximum spacing of ties = 310 mm
Pier 7 - CSA-S6 Design Requirements
Section Diameter: 800 mm
Story height = 14.8 m
Circular Section: Diameter = 800 mm
Pier 8 - CSA-S6 Main Reinforcement
Axial load: = -4482.99 kN
Major axis Moment M, end 1, = -1021.27 kNm
end 2, = 504.39 kNm
Minor axis moment M, end 1, = -22.77 kNm
end 2, = 11.34 kNm
60
Cm = 0.40
ds = 1.00
Cm = 0.40
ds = 1.00
Area of steel provided = 6600 mm2
Axial compression capacity = -4482.99 kN
Resultant moment capacity Mz = 1009.03 kNm
Actual distance between bars = 77 mm
Pier 7 - CSA-S6 Shear Reinforcement
Actual spacing of ties = 300 mm
Major Axis:
Design shear force Vf = 106.26 kN
Shear resisted by concrete
Vc = Φcλβ√fc'bwdv (4.1)
= 0.65 x 1.00 x 0.297 x √30.00 x 800.00 x 576.00 = 483.88 kN
Shear resisted by steel
Vs =𝜙𝑠𝐴𝑣𝑓𝑦𝑡𝑑𝑣𝑐𝑜𝑡𝜃
𝑠 (4.2)
= 0.85 · 0.67 · 400.00 · 576.00 · 1.69 = 220.22 kN
Maximum shear capacity
Vr,max = 0.25Φc fc'bwdv (4.3)
= 0.25 x 0.65 x 30.00 x 800.00 x 576.00 = 2246.40 kN
Vr = 483.88 + 220.22 = 704.10 kN
Vr > Vf = OK
Actual area of shear reinforcement (2-10M) = 200 mm2
Maximum spacing of ties = 310 mm
Minor Axis:
Design shear force Vf = 25.07 kN
Shear resisted by concrete
Vc = Φcλβ√fc'bwdv (4.1)
= 0.65 · 1.00 · 0.295 · √30.00 · 800.00 · 576.00 = 483.88 kN
61
Shear resisted by steel
Vs =𝜙𝑠𝐴𝑣𝑓𝑦𝑡𝑑𝑣𝑐𝑜𝑡𝜃
𝑠 (4.2)
= 0.85 x 0.67 x 400.00 x 576.00 x 1.69 = 220.22 kN
Maximum shear capacity
Vr,max = 0.25Φc fc'bwdv (4.3)
= 0.25 x 0.65 x 30.00 x 800.00 x 576.00 = 2246.40 kN
Vr = 483.88 + 220.22 = 704.10 kN
Vr > Vf = OK
Actual area of shear reinforcement (2-10M) = 200 mm2
Maximum spacing of ties = 310 mm
4.6 Response of Bridge to Loading and Effects of Scouring In
Projected Climate
The same bridge was analyzed for conditions in the projected climate. The vehicle loads, wind
loads and self-weight of the structure were kept constant, while the scour depth and hydrodynamic
pressure were varied accordingly. The response of the bridge elements was then determined using
the new conditions.
4.6.1 Axial and shear forces
The maximum axial forces on pier 7 and 8 remained constant because there was no increment in
factors contributing to the axial forces. The maximum shear forces, however, had increased. This
is due to the increase in scour depths and the hydrodynamic pressure on the piers. The maximum
shear force on pier 7 for the controlling load combination had increased from 106 kN to 149 kN
for the projected climate as shown below in Figure 4.16. While for pier 8, the maximum shear
force increased to 107 kN as shown in Figure 4.17.
62
Figure 4.16 Shear force envelope for pier 7 in projected climate
Figure 4.17 Shear force envelope for pier 8 in projected climate
4.6.2 Bending moments and design requirements
The maximum bending moments on the bridge elements for the critical piers has increased. The
maximum bending moment in pier 7 increased from 1021 kNm to 1042 kNm while the maximum
bending moment for pier 8 increased from 1018 kNm to 1032 kNm. These increments in the
maximum bending moment were due to the increase in scour depths, water flow velocity and the
depth of flow. Figure 4.18 and Figure 4.19 show the bending moment envelopes for both piers.
63
Figure 4.18 Bending moment envelope for pier 7 in projected climate
Figure 4.19 Bending moment envelope for pier 8 in projected climate
The piers were designed according to the Canadian standard concrete design code to estimate the
reinforcement requirement for the piers in the projected climate scenario.
Pier 7 - CSA-S6 Design Requirements
Section Diameter : 800 mm
Story height = 14.8 m
Circular Section: Diameter = 800 mm
CSA-S6 Main Reinforcement
Axial Load: = -4484.04 kN
Major axis moment M, end 1, = 1042.21 kNm
end 2, = -533.30 kNm
Minor axis moment M, end 1, = -22.77 kNm
end 2, = 11.34 kNm
64
ds = 1.00
Cm = 0.40
Area of steel provided = 7500 mm2
Axial compression capacity = -4484.04 kN
Resultant moment capacity Mz = -1066.84 kNm
Actual distance between bars = 66 mm
Pier 7 - CSA-S6Shear Reinforcement
Actual spacing of ties = 300 mm
Major Axis:
Design shear force Vf = 106.60 kN
Shear resisted by concrete Vc
Vc = Φcλβ√fc'bwdv (4.1)
= 0.65 x 1.00 x 0.297 x √30.00 x 800.00 x 576.00 = 487.07 kN
Shear resisted by steel
Vs =𝜙𝑠𝐴𝑣𝑓𝑦𝑡𝑑𝑣𝑐𝑜𝑡𝜃
𝑠 (4.2)
= 0.85 x 0.67 x 400.00 x 576.00 x 1.69 = 220.58 kN
Maximum shear capacity
Vr,max = 0.25Φc fc'bwdv (4.3)
= 0.25 x 0.65 x 30.00 x 800.00 x 576.00 = 2246.40 kN
Vr = 487.07 + 220.58 = 707.66 kN
Vr > Vf = OK
Minimum density of links = 0.67
Shear density of rebar provided = 0.67
Actual area of shear reinforcement (2-10M) = 200 mm2
Maximum spacing of ties = 310 mm
Minor Axis:
Design shear force Vf = 22.12 kN
Shear resisted by concrete
Vc = Φcλβ√fc'bwdv (4.1)
= 0.65 x 1.00 x 0.297 x √30.00 x 800.00 x 576.00 = 487.07 kN
65
Shear resisted by steel
Vs =𝜙𝑠𝐴𝑣𝑓𝑦𝑡𝑑𝑣𝑐𝑜𝑡𝜃
𝑠 (4.2)
= 0.85 x 0.67 x 400.00 x 576.00 x 1.69 = 220.58 kN
Maximum shear capacity
Vr,max = 0.25Φc fc'bwdv (4.3)
= 0.25 x 0.65 x 30.00 x 800.00 x 576.00 = 2246.40 kN
Vr = 487.07 + 220.58 = 707.66 kN
Vr > Vf = OK
Actual area of shear reinforcement (2-10M) = 200 mm2
Maximum spacing of ties = 310 mm
Pier 8 - CSA-S6Design Requirements
Section Property: 800 mm
Story height = 14.8 m
Circular Section: Diameter = 800 mm
Pier 8 - CSA-S6Main Reinforcement
Axial load: = -4482.67 kN
Major axis moment M, end 1, =-1032.43 kNm
end 2, = 471.07 kNm
Minor axis moment M, end 1, = -22.77 kNm
end 2, = 11.34 kNm
Cm = 0.40 Eq. 10-20
ds = 1.00 Eq. 10-24
Area of steel provided = 6900 mm2
Axial compression capacity = -4482.67 kN
Resultant moment capacity Mz = 1032.43 kNm
Actual distance between bars = 73 mm
Pier 8 CSA-S6 Shear Reinforcement
Actual spacing of ties = 300 mm
Major Axis:
66
Design shear force Vf = 100.85 kN
Shear resisted by concrete
Vc = Φcλβ√fc’bwdv (4.1)
= 0.65 x 1.00 x 0.297 x √30.00 x 800.00 x 576.00 = 460.91 kN
Shear resisted by steel
Vs =𝜙𝑠𝐴𝑣𝑓𝑦𝑡𝑑𝑣𝑐𝑜𝑡𝜃
𝑠 (4.2)
= 0.85 x 0.67 x 400.00 x 576.00 x 1.67 = 217.48 kN
Maximum shear capacity
Vr,max = 0.25Φc fc'bwdv (4.3)
= 0.25 x 0.65 x 30.00 x 800.00 x 576.00 = 2246.40 kN
Vr = 460.91 + 217.48 = 678.39 kN
Vr > Vf = OK
Minimum density of links = 0.67
Shear density of rebar provided = 0.67
Actual area of shear reinforcement (2-10M) = 200 mm2
Maximum spacing of ties = 310 mm
Minor Axis:
Design shear force Vf = 25.07 kN
Shear resisted by concrete
Vc = Φcλβ√fc'bwdv (4.1)
= 0.65 x 1.00 x 0.297 x √30.00 x 800.00 x 576.00 = 460.91 kN
Shear resisted by steel
Vs =𝜙𝑠𝐴𝑣𝑓𝑦𝑡𝑑𝑣𝑐𝑜𝑡𝜃
𝑠 (4.2)
= 0.85 x 0.67 x 400.00 x 576.00 x 1.67 = 217.48 kN
Maximum shear capacity
Vr,max = 0.25Φc fc'bwdv (4.3)
= 0.25 x 0.65 x 30.00 x 800.00 x 576.00 = 2246.40 kN
Vr = 460.91 + 217.48 = 678.39 kN
Vr > Vf = OK
Actual area of shear reinforcement (2-10M) = 200 mm2
67
Table 4.1- Summary of Bending Moment, Shear Force and reinforcement requirements
Present climate Projected climate
Pier 7 Pier 8 Pier 7 Pier 8
Bending Moments ( kNm) 1021 1018 1042 1032
Shear forces (kN) 106 104 149 107
Required reinforcement (mm) 6900 6600 7500 6900
4.7 Effects of Age and Exposure Conditions and Climate
Change Interactions on Concrete Infrastructures
Bridge infrastructures and other infrastructure built with concrete and steel ages, they deteriorate
due to effects of environmental loading that they are exposed to. These deteriorations result in
spalling (loss of concrete), which ultimately reduces the sectional dimensions of the member and
also the loss of reinforcement. These losses combine to reduce the strength of the members. In a
changing climate where the rate of deterioration is exacerbated, the effects of age and exposure
conditions on existing infrastructures such as a bridge is somewhat difficult to predict since
different exposure conditions will have different effects and are difficult to be simulated
accurately.
Experimental analysis by several researchers has in the past tried to predict residual strength based
on accelerated corrosion of reinforced, prestressed and fiber reinforced concrete elements. Other
methods used to estimate the residual strength of reinforced concrete has been done by testing
structural elements from de-commissioned structures or by coring and testing of samples.
Dasar et al. (2017) tested performance reduction of 40-year-old reinforced concrete beams in
natural corrosion environments and reported that for every 1% of local cross-sectional loss in the
tensile steel bars, a 0.9% reduction in the load-carrying capacity of the reinforced concrete beams
occurs. Rodriguez et al. (as cited in Dasar et al. 2017) had reported that a corrosion degree of about
14% caused beam strength to decrease by 23%.
The present study did not investigate the effect of climate change on the age and exposure
conditions of the bridge, but it is worthy to note that the effects of climate change will compound
the strength loss due to age and exposure conditions.
68
5 Conclusion and recommendations
A study was carried out to investigate the impact of climate change on bridge infrastructure and to
investigate adaptation measures to protect the bridges against these impacts. A bridge on the
Ottawa river was used as case study. The model was constructed to study the effect of increased
scour depth and increased flood load on the existing bridge. The bridge model was idealized as a
beam bridge which consists of a 250 mm reinforced concrete deck on 7 reinforced concrete girders
spanning continuously over eight 20 m spans. The transverse width of the deck is 17 m and carries
4 lanes of highway each 3.5 m wide. On each extreme side is a shoulder of 1.5 m wide each. The
center to center spacing between girders is 2.143 m with deck overhangs of 1.0 m on either side.
The girders are supported on beams of 800 mm by 1000 mm depths. Each beam is in turn supported
on two 800mm diameter piers, and each has a length of 14.78 m from the top of the pile cap
The model was analyzed for traffic, wind, hydrostatic and other ancillary loads. Results of analysis
for a 100-year storm were compared with results of the analysis for a 100-year storm in a projected
climate. Results show that in a projected climate, increased scour depths and hydrodynamic load
effects on the bridge piers caused an increase in the shear forces and bending moment and will
jeopardize the safety of the bridge. Adaptation measures will have to be carried out to retrofit the
bridge to make it safe for use.
5.1 Adapting To Climate Change
River bridge infrastructures can be adapted to the effects of climate change by using the traditional
methods of bridge retrofitting or rehabilitation as a result of strength and material deterioration.
This is so because even though climate change is a separate phenomenon on its own, its mechanism
of effects on infrastructure is by speeding up the rate of deterioration and by increasing physical
loads that a structure has to resist.
5.1.1 Jacketing
Jacketing is the process whereby a section of an existing structural member is restored to original
dimensions or increased in size by encasement using suitable materials. A steel reinforcement cage
69
or composite material wrap can be constructed around the damaged section onto which shotcrete
or cast-in- place concrete is placed.
For jacketing, the void between the form and the existing member is filled using pumping, or
preplaced aggregate concrete. Jacketing is particularly used for the repair of deteriorated columns,
piers, and piles and may easily be employed in underwater applications. It is suggested that the
bridge piers should be jacketed to increase the shear and moment capacities to meet with the
capacity required for the projected climate. Figure 5.1shows a typical cross section of a jacketed
pier.
Figure 5.1 Typical cross section of a pier before and after jacketing
5.1.2 Scour Protection
From the present study, it is evident that the single most important effect of climate change on
river bridge infrastructure that jeopardizes the safety of bridge and users is scouring as a result of
a flood. A way to protect and adapt this bridge is by protection against scour. Many scour
protection methods have been studied and deployed in bridges susceptible to scouring. The
following scour protection method is suggested to be investigated and if found appropriate be
deployed to protect against scour of the bridge
5.1.2.1 Riprap
Riprap is one of the most commonly used bridge pier scour protection measures. it consists of
large stones placed around a pier to armor the bed. This armoring prevents the strong vortex flow
at the front of the pier from entraining bed sediment and forming a scour hole. The ability of the
70
riprap layer to provide scour protection is a function of stone size. Stones are sized such that the
current of flowing water is not adequate to displace the ripraps. Design and sizing of riprap stones
is described in HEC-23 (Lagasse et al. 2006).
Sizing of riprap stones can be determined using the Isbash formula for sizing riprap on a channel
bed (Lagasse et al. 2006).
d50 =0.692(𝑘𝑉)2
(𝑆𝑠−1)2𝑔 (4.4)
d50 = Riprap size (m)
V = Design velocity (m/s)
k = Coefficient for pier shape
Ss = Specific gravity of the riprap
g = Acceleration of gravity (9.81 m/s2)
In ripraps, filters are used in combinations with the stones, and filters should be a combination of
geotextile and granular materials.
The selection of geotextile can be based on methods outlined by Koerna (1998), HEC-11 or
AASHTO M-288 (Lagasse et al., 2006). Lagasse et al. (2006) advocated the use of Koerna method
as it places more emphasis on permeability and less emphasis on particle retension. Geotextile
application should exhibit a permeability that is more than 4 times greater than the bed material,
that is Kg/Ks >4.0 (Lagasse et al., 2006). Kg and Ks are permeability of geotextile and bed materials
respectively.
For the granullar filters, the requirement is the compatibility of the filter with the sand bed material
in terms of both particle retention and permeability. By defining upper and lower limits of d15 for
the filter, the largest size allowable to maintain particle retention and smallest size allowable to
ensure the filter has greater permeability than the sand is established. The requirements for the
filter to soil relationship are as follows:
𝑑15 𝑓𝑖𝑙𝑡𝑒𝑟
𝑑85 𝑠𝑜𝑖𝑙< 5 (4.5)
5 <𝑑15 𝑓𝑖𝑙𝑡𝑒𝑟
𝑑15 𝑠𝑜𝑖𝑙< 40 (4.6)
71
The d85 of the filter must be large enough so that the filter does not pass through the riprap. The
requirements for filter to riprap relationship are
𝑑15 𝑟𝑖𝑝𝑟𝑎𝑝
𝑑85 𝑓𝑖𝑙𝑡𝑒𝑟< 5 (4.7)
5.2 Future Study
1 This research studied impact of a changing climate on a river bridge infrastructure. On
the particular bridge studied as case study, the scour depth was such that the bridge
foundations have not been impacted. There would be bridges and scour depths that may
be deep enough to affect foundations. Research should in future be carried out for such
cases.
2 Material deterioration caused by climate change need to be studied. Infrastructures may
be more impacted by chemical reactions as a result of increased environmental loads
rather than physical loads.
3 Apart from new built infrastructure and normally existing infrastructure, some
infrastructure has experienced extreme event prior in their service life. This type of
infrastructure will likely behave differently in a changing climate. Research should be
conducted to study climate change interaction with such infrastructures.
4 In some zones of the world, climate change causes a reduction in environmental loads
and factors. Some zones will experience reduced temperature, precipitation and even
desertification in extremes. A study of how civil infrastructures will be impacted in
such zones need be studied.
72
Appendices
Appendix 1 Output table of hydraulic analysis
Reach River
Sta Profile Q Total
Min Ch
El
W.S.
Elev
Crit
W.S.
E.G.
Elev
E.G.
Slope
Vel
Chnl
Flow
Area
Top
Width
Froude
# Chl
(m3/s) (m) (m) (m) (m) (m/m) (m/s) (m2) (m)
Ottawa 4970 PF 1 8190 44.55 51.06 51.39 0.0016 2.74 3360.4 719.7 0.36
Ottawa 4970 PF 3 9828 44.55 51.88 52.21 0.0014 2.8 3964.7 766.88 0.34
Ottawa 4694.7 PF 1 8190 43 50.09 47.56 50.79 0.0027 3.8 2220.8 424.08 0.47
Ottawa 4694.7 PF 3 9828 43 50.96 47.99 51.66 0.0026 3.99 2698.4 445.31 0.47
Ottawa 4640.4 Bridge
Ottawa 4430.3 PF 1 8190 42 48.2 48.98 0.0037 4.03 2155.5 456.95 0.54
Ottawa 4430.3 PF 3 9828 42 48.83 49.7 0.0036 4.29 2442.7 459.67 0.54
Ottawa 4139.6 PF 1 8190 41 47.5 48.05 0.0024 3.31 2508.5 464.8 0.44
Ottawa 4139.6 PF 3 9828 41 48.13 48.77 0.0024 3.57 2811 491.33 0.45
Ottawa 3875.3 PF 1 8190 41 47.11 47.48 0.0016 2.71 3076.4 579.81 0.36
Ottawa 3875.3 PF 3 9828 41 47.76 48.19 0.0016 2.91 3485 675.93 0.37
Ottawa 3552.6 PF 1 8190 40 46.92 43.03 47.1 0.0007 1.87 4406.5 719.74 0.24
Ottawa 3552.6 PF 3 9828 40 47.58 43.34 47.79 0.0007 2.03 4911 805.8 0.25
73
Ottawa 3222.7 PF 1 8190 40 46.26 42.95 46.51 0.0012 2.2 3724.1 693.74 0.3
Ottawa 3222.7 PF 3 9828 40 46.88 43.3 47.17 0.0012 2.38 4158.1 711.04 0.31
Ottawa 2895.2 PF 1 8190 39.45 45.97 46.17 0.0008 2.01 4092.6 683.04 0.26
Ottawa 2895.2 PF 3 9828 39.45 46.58 46.82 0.0009 2.19 4509.8 685.77 0.27
Ottawa 2549.7 PF 1 8190 39 45.71 45.9 0.0007 1.95 4230.9 706.47 0.24
Ottawa 2549.7 PF 3 9828 39 46.3 46.53 0.0008 2.14 4671.3 781.83 0.26
Ottawa 2351.8 PF 1 8190 39 45.5 45.72 0.001 2.17 4137.5 986.25 0.29
Ottawa 2351.8 PF 3 9828 39 46.1 46.35 0.0011 2.31 4750.8 1049.9 0.29
Ottawa 1871.8 PF 1 8190 39 45.3 45.4 0.0004 1.42 6095 1334.6 0.18
Ottawa 1871.8 PF 3 9828 39 45.9 46.01 0.0004 1.53 6915.7 1380.1 0.19
Ottawa 1431.1 PF 1 8190 39 45.12 45.21 0.0004 1.39 6458.6 1475.3 0.18
Ottawa 1431.1 PF 3 9828 39 45.72 45.83 0.0004 1.47 7367.3 1557.8 0.18
Ottawa 1059.9 PF 1 8190 39 44.92 45.04 0.0005 1.52 5578.6 1313 0.2
Ottawa 1059.9 PF 3 9828 39 45.52 45.65 0.0005 1.63 6385.2 1374.9 0.21
Ottawa 633.54 PF 1 8190 39 44.54 41.36 44.73 0.001 1.95 4302 985.74 0.28
Ottawa 633.54 PF 3 9828 39 45.13 41.66 45.34 0.001 2.07 4897 1036 0.28
74
Appendix 2 Historical discharge data for Ottawa river measured at Carillon (Ottawa river regulation planning board)
MONTHLY AND ANNUAL MEAN DISCHARGES IN CUBIC METRES PER SECOND FROM 1964 ANNUAL EXTREMES
YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL MEANS
DAILY MAXIMUM
DAILY MINIMUM
1964 1471 1436 1782 2564 2227 1754 1256 924 851 990 1028 1232 1459 3726 560 1965 1257 1286 1426 2078 2851 1511 1017 1247 1785 3163 2605 2243 1876 3672 570 1966 2147 1908 2648 3197 2635 2254 1336 1481 1240 1397 1917 3422 2133 5410 840
1967 2220 2221 1737 4256 3924 3157 2106 1363 1306 2112 3374 2265 2500 5407 974 1968 2016 1913 2339 3480 1799 1596 1659 1280 1184 1150 1223 1361 1748 4653 805
1969 1453 1510 1644 3293 3499 2217 1595 1440 1101 1235 2135 1958 1924 5134 771 1970 1592 1480 1543 2925 3553 2470 2261 1698 1228 1379 1609 1525 1941 4990 842 1971 1396 1354 1484 3512 3536 1579 997 952 880 870 907 1172 1553 5704 306
1972 1224 1163 1253 3169 4806 2374 2195 2046 1850 1940 2614 2073 2228 6329 863 1973 1975 2071 3615 4137 3841 2765 2065 1563 1362 1665 1703 1904 2390 5703 1086 1974 1726 1678 2307 3883 6496 4349 2210 1299 1069 1235 1968 2025 2524 8105 611 1975 1922 1748 2005 3206 3057 2060 1109 866 826 975 1162 1612 1711 5790 613 1976 1553 1546 2338 5767 3861 1882 1548 1252 1125 1217 1231 1437 2061 8190 704
1977 1351 1201 2677 3743 2326 1134 1121 930 973 1323 1571 2012 1699 5062 617 1978 1966 1902 1499 3169 2923 1537 1069 958 844 1263 1231 1286 1634 4668 701 1979 1454 1428 2537 4113 5023 2231 1466 1273 1296 1934 2483 2850 2346 6686 998 1980 2332 1948 2182 3574 2736 1484 1431 1420 1300 2175 2294 1919 2066 5329 683 1981 1603 2813 3116 4309 2996 2759 1582 1203 1706 1741 2027 1563 2276 6222 907
1982 1394 1374 1558 3176 2283 1426 1100 851 852 1030 1580 2259 1573 4585 684 1983 2381 2176 2571 2914 4915 3049 1237 1039 896 1081 1581 1787 2136 6907 567 1984 1640 1978 2069 4444 2916 2492 1964 1435 1306 1245 1925 2054 2119 5568 873 1985 2094 2015 2699 3646 3793 1539 1340 1623 1134 1109 1350 1593 1995 6004 901 1986 1620 1676 1647 3353 2769 2083 1322 1351 1401 1801 1829 1742 1881 4647 988
1987 1683 1563 1910 3111 1176 1201 985 816 771 926 1325 1846 1440 4767 614 1988 1868 1933 1649 3708 2788 1247 915 1176 1268 2289 3457 2251 2042 4665 826 1989 2062 2107 1888 2959 2986 2666 1287 920 854 933 1841 1859 1859 3883 566 1990 1919 2061 2499 3222 2628 1552 1444 1018 897 1829 2180 2829 2006 4562 775 1991 2262 2235 2412 4796 2542 1312 893 778 842 1177 1502 1881 1881 6728 666
1992 1827 1820 1678 3150 2998 1238 1163 1003 1443 1859 2688 2202 1921 5337 806 1993 2169 1883 1493 3746 1784 1873 1070 879 942 1896 2416 2216 1859 5454 733 1994 1718 1947 1814 2840 2572 2187 2186 1705 1133 1122 1670 1790 1889 4600 965 1995 2537 2215 2583 1757 2382 2216 1050 954 699 987 1986 1830 1764 3976 588 1996 2054 2291 2043 3034 4212 1944 1582 1387 1036 1237 1705 1915 2036 5722 876
1997 2016 2160 2270 4094 4693 1876 1497 990 972 1033 1437 1408 2035 6382 798 1998 1589 1554 2290 4687 1396 1107 1177 796 762 819 910 1388 1536 7239 535 1999 1737 1959 1921 3295 1279 1420 1355 880 832 1652 2444 2738 1789 5401 716 2000 2090 2003 2382 2847 2712 1842 1559 1392 1226 1016 1098 1485 1804 4274 617 2001 1449 1657 1518 2872 1756 1439 1016 668 822 1837 2561 2798 1697 4081 552
75
2002 2185 1970 2354 4171 3951 3691 1858 1105 886 826 900 956 2068 5894 638 2003 1167 1249 1488 2373 1868 1725 1127 1487 1008 1816 3266 3096 1807 4718 788 2004 2470 2040 2289 3217 3865 1936 1875 1091 1255 881 1095 1575 1966 4909 636
2005 1942 1736 1373 4141 2499 1570 993 780 698 1068 1614 2258 1720 4824 532 2006 2201 2308 2468 4144 2444 1568 1427 1360 1201 2591 3377 3299 2364 4587 945 2007 2823 2176 2049 2841 1722 1979 1411 826 720 707 849 1221 1606 3635 566 2008 2513 2243 2140 4783 3228 2027 2318 2182 1472 1323 1793 2085 2341 6052 1036 2009 2336 2220 2550 4193 3358 2244 1951 1886 1169 1349 1916 1936 2258 5617 897
2010 1872 1949 2308 1614 948 789 730 640 981 1896 1867 2711 1524 3922 467 2011 2224 2010 2477 3423 3640 2106 1465 899 832 876 1157 1881 1915 4931 609 2012 1924 1909 3248 2315 1692 987 620 614 703 1223 2052 1843 1593 4810 492 2013 2037 2370 2180 4037 4533 3244 1393 942 992 1440 2745 1980 2319 5421 816 2014 2038 1991 1470 3749 4613 2368 1341 1120 1492 2300 2461 2302 2270 5213 900
2015 2188 2008 1571 2929 2391 1724 1046 989 1057 874 1432 2408 1715 4422 715 2016 2785 2588 3713 4843 3204 1900 1059 932 822 892 978 1582 2105 5833 630 2017 1823 2030 3028 5431 6103 --- --- --- --- --- --- --- --- 8862 1418 Mean 1913 1889 2143 3523 3088 1975 1411 1164 1081 1410 1850 1979 1942 5356 744
YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANNUAL MEANS
DAILY MAXIMUM
DAILY MINIMUM
76
Appendix 3 Scour calculations input and output for 100- year storm
Contraction Scour
Left Channel Right
Input Data
Average Depth (m): 5.06 6.09 3.10
Approach Velocity (m/s): 2.42 3.80 1.84
Br Average Depth (m): 4.74 4.11
BR Opening Flow (m3/s): 3946.79 4243.21
BR Top WD (m): 149.86 155.34
Grain Size D50 (mm): 0.05 0.05 0.05
Approach Flow (m3/s): 1249.34 5198.60 1742.06
Approach Top WD (m): 102.23 311.47 305.99
K1 Coefficient: 0.690 0.690 0.690
Results
Scour Depth Ys (m): 3.23 6.50
Critical Velocity (m/s): 0.31 0.28
Equation: Live Live
Pier Scour
All piers have the same scour depth
Input Data
Pier Shape: Circular cylinder
Pier Width (m): 0.8
Grain Size D50 (mm): 0.05000
Depth Upstream (m): 6.68
Velocity Upstream (m/s): 3.80
K1 Nose Shape: 1.00
Pier Angle: 0.00
Pier Length (m): 14.00
K2 Angle Coef: 1.00
K3 Bed Cond Coef: 1.10
77
Grain Size D90 (mm): 1.00000
K4 Armouring Coef: 1.00
Results
Scour Depth Ys (m): 3.09
Froude #: 0.47
Equation: CSU equation
Combined Scour Depths
Pier Scour + Contraction Scour (m):
Channel: 6.32
Appendix 4 Scour calculations input and output for 100- year storm in projected climate
Contraction Scour
Left Channel Right
78
Input Data
Average Depth (m): 5.62 6.90 3.48
Approach Velocity (m/s): 2.44 3.99 1.93
Br Average Depth (m): 5.21 4.48
BR Opening Flow (m3/s): 4655.78 5172.21
BR Top WD (m): 149.06 158.45
Grain Size D50 (mm): 0.05 0.05 0.05
Approach Flow (m3/s): 1467.30 6023.46 2337.24
Approach Top WD (m): 107.20 311.47 348.21
K1 Coefficient: 0.690 0.690 0.690
Results
Scour Depth Ys (m): 3.99 7.35
Critical Velocity (m/s): 0.31 0.28
Equation: Live Live
Pier Scour
All piers have the same scour depth
Input Data
Pier Shape: Circulare cylinder
Pier Width (m): 0.8m
Grain Size D50 (mm): 0.05000
Depth Upstream (m): 7.23
Velocity Upstream (m/s): 3.99
K1 Nose Shape: 1.00
Pier Angle: 0.00
Pier Length (m): 14.00
K2 Angle Coef: 1.00
K3 Bed Cond Coef: 1.10
Grain Size D90 (mm): 1.00000
K4 Armouring Coef: 1.00
Results
Scour Depth Ys (m): 3.19
79
Froude #: 0.47
Equation: CSU equation
Combined Scour Depths
Pier Scour + Contraction Scour (m):
Channel: 7.18
80
Appendix 5 STAAD Pro input for 100-year design
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 23-Jan-17
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
2 0 5 0; 4 13.2 5 0; 5 14.2 5 0; 6 -1 5 0; 8 0 5 20; 10 13.2 5 20;
11 14.2 5 20; 12 -1 5 20; 14 0 5 40; 16 13.2 5 40; 17 14.2 5 40; 18 -1 5 40;
20 0 5 60; 22 13.2 5 60; 23 14.2 5 60; 24 -1 5 60; 26 0 5 80; 28 13.2 5 80;
29 14.2 5 80; 30 -1 5 80; 32 0 5 100; 34 13.2 5 100; 35 14.2 5 100;
36 -1 5 100; 37 1.65 5 0; 38 1.65 5 20; 39 1.65 5 40; 40 1.65 5 60;
41 1.65 5 80; 42 1.65 5 100; 43 3.3 5 0; 44 3.3 5 20; 45 3.3 5 40; 46 3.3 5 60;
47 3.3 5 80; 48 3.3 5 100; 49 4.95 5 0; 50 4.95 5 20; 51 4.95 5 40;
52 4.95 5 60; 53 4.95 5 80; 54 4.95 5 100; 55 6.6 5 0; 56 6.6 5 20;
57 6.6 5 40; 58 6.6 5 60; 59 6.6 5 80; 60 6.6 5 100; 61 8.25 5 0; 62 8.25 5 20;
63 8.25 5 40; 64 8.25 5 60; 65 8.25 5 80; 66 8.25 5 100; 67 9.9 5 0;
68 9.9 5 20; 69 9.9 5 40; 70 9.9 5 60; 71 9.9 5 80; 72 9.9 5 100; 73 11.55 5 0;
74 11.55 5 20; 75 11.55 5 40; 76 11.55 5 60; 77 11.55 5 80; 78 11.55 5 100;
79 0 5 120; 80 13.2 5 120; 81 14.2 5 120; 82 -1 5 120; 83 1.65 5 120;
84 3.3 5 120; 85 4.95 5 120; 86 6.6 5 120; 87 8.25 5 120; 88 9.9 5 120;
89 11.55 5 120; 90 0 5 -20; 91 13.2 5 -20; 92 14.2 5 -20; 93 -1 5 -20;
94 1.65 5 -20; 95 3.3 5 -20; 96 4.95 5 -20; 97 6.6 5 -20; 98 8.25 5 -20;
99 9.9 5 -20; 100 11.55 5 -20; 109 0 5 -40; 110 13.2 5 -40; 111 14.2 5 -40;
112 -1 5 -40; 113 1.65 5 -40; 114 3.3 5 -40; 115 4.95 5 -40; 116 6.6 5 -40;
117 8.25 5 -40; 118 9.9 5 -40; 119 11.55 5 -40; 120 0 -9.78 100;
121 13.2 -9.78 100; 122 0 -9.78 -20; 123 13.2 -9.78 -20; 124 0 -9.78 0;
125 13.2 -9.78 0; 126 0 -9.78 80; 127 13.2 -9.78 80; 128 0 -9.78 20;
129 13.2 -9.78 20; 130 0 -9.78 60; 131 13.2 -9.78 60; 132 0 -9.78 40;
133 13.2 -9.78 40;
81
MEMBER INCIDENCES
1 93 90; 2 6 2; 3 12 8; 4 18 14; 5 24 20; 6 30 26; 7 36 32; 8 90 122; 9 2 124;
10 8 128; 11 14 132; 12 20 130; 13 26 126; 14 32 120; 15 90 109; 16 2 90;
17 8 2; 18 14 8; 19 20 14; 20 26 20; 21 32 26; 22 79 32; 23 90 94; 24 2 37;
25 8 38; 26 14 39; 27 20 40; 28 26 41; 29 32 42; 30 94 113; 31 37 94; 32 38 37;
33 39 38; 34 40 39; 35 41 40; 36 42 41; 37 83 42; 38 94 95; 39 37 43; 40 38 44;
41 39 45; 42 40 46; 43 41 47; 44 42 48; 45 95 114; 46 43 95; 47 44 43;
48 45 44; 49 46 45; 50 47 46; 51 48 47; 52 84 48; 53 95 96; 54 43 49; 55 44 50;
56 45 51; 57 46 52; 58 47 53; 59 48 54; 60 96 115; 61 49 96; 62 50 49;
63 51 50; 64 52 51; 65 53 52; 66 54 53; 67 85 54; 68 96 97; 69 49 55; 70 50 56;
71 51 57; 72 52 58; 73 53 59; 74 54 60; 82 97 116; 83 55 97; 84 56 55;
85 57 56; 86 58 57; 87 59 58; 88 60 59; 89 86 60; 90 97 98; 91 55 61; 92 56 62;
93 57 63; 94 58 64; 95 59 65; 96 60 66; 97 98 117; 98 61 98; 99 62 61;
100 63 62; 101 64 63; 102 65 64; 103 66 65; 104 87 66; 105 98 99; 106 61 67;
107 62 68; 108 63 69; 109 64 70; 110 65 71; 111 66 72; 112 99 118; 113 67 99;
114 68 67; 115 69 68; 116 70 69; 117 71 70; 118 72 71; 119 88 72; 120 99 100;
121 67 73; 122 68 74; 123 69 75; 124 70 76; 125 71 77; 126 72 78; 127 100 119;
128 73 100; 129 74 73; 130 75 74; 131 76 75; 132 77 76; 133 78 77; 134 89 78;
135 100 91; 136 73 4; 137 74 10; 138 75 16; 139 76 22; 140 77 28; 141 78 34;
142 91 123; 143 4 125; 144 10 129; 145 16 133; 146 22 131; 147 28 127;
148 34 121; 149 91 110; 171 4 91; 172 10 4; 173 16 10; 174 22 16; 175 28 22;
176 34 28; 177 80 34; 178 91 92; 179 4 5; 180 10 11; 181 16 17; 182 22 23;
183 28 29; 184 34 35;
ELEMENT INCIDENCES SHELL
150 82 81 35 36; 151 36 35 29 30; 152 30 29 23 24; 153 24 23 17 18;
154 18 17 11 12; 155 12 11 5 6; 156 6 5 92 93; 187 93 92 111 112;
DEFINE PMEMBER
1 23 38 53 68 90 105 120 135 178 PMEMBER 1
4 26 41 56 71 93 108 123 138 181 PMEMBER 2
3 25 40 55 70 92 107 122 137 180 PMEMBER 3
ELEMENT PROPERTY
82
150 TO 156 187 THICKNESS 0.35
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 2.17185e+007
POISSON 0.17
DENSITY 23.5616
ALPHA 1e-005
DAMP 0.05
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
15 TO 22 30 TO 37 45 TO 52 60 TO 67 82 TO 89 97 TO 104 112 TO 119 127 TO 134 -
149 171 TO 177 PRIS YD 1 ZD 0.6 YB 0.75 ZB 0.25
1 TO 7 23 TO 29 38 TO 44 53 TO 59 68 TO 74 90 TO 96 105 TO 111 120 TO 126 -
135 TO 141 178 TO 184 PRIS YD 1 ZD 0.8
8 TO 14 142 TO 148 PRIS YD 0.8
CONSTANTS
BETA 180 MEMB 15 TO 22 30 TO 37 45 TO 52 60 TO 67 82 TO 89 97 TO 104 -
112 TO 119 127 TO 134 149 171 TO 177
MATERIAL CONCRETE ALL
SUPPORTS
79 TO 89 109 TO 119 PINNED
120 TO 133 FIXED
DEFINE MOVING LOAD
TYPE 1 LOAD 25 62.5 62.5 87.5 75
DIST 3.6 1.2 6.6 6.6 WID 1.8
TYPE 2 LOAD 25 62.5 62.5 87.5 75
DIST 3.6 1.2 6.6 6.6 WID 1.8
TYPE 3 LOAD 25 62.5 62.5 87.5 75
DIST 3.6 1.2 6.6 6.6 WID 1.8
TYPE 4 LOAD 25 62.5 62.5 87.5 75
DIST 3.6 1.2 6.6 6.6 WID 1.8
83
LOAD 1 LOADTYPE Dead TITLE SELF WEIGHT
SELFWEIGHT Y -1
LOAD 2 LOADTYPE Dead TITLE VERTICAL WIND
ELEMENT LOAD
150 TO 156 187 PR GY -1.38
LOAD 3 LOADTYPE Dead TITLE HORIZONTAL WIND
MEMBER LOAD
8 TO 14 142 TO 148 UNI GX -2.208 0 3.46
LOAD 5 LOADTYPE Dead TITLE HYDRODYNAMIC LOAD
MEMBER LOAD
8 TO 14 142 TO 148 UNI GX -4.28 3.42 13.92
LOAD GENERATION 20
TYPE 1 1.2 5 -40 ZINC 8
LOAD GENERATION 20
TYPE 2 4.2 5 -40 ZINC 8
LOAD GENERATION 20
TYPE 3 7.2 5 -40 ZINC 8
LOAD GENERATION 20
TYPE 4 10.2 5 -40 ZINC 8
LOAD 87 LOADTYPE Dead TITLE WEARING SURFACE
ELEMENT LOAD
150 TO 156 187 PR GY -0.01
LOAD COMB 86 COMBINATION LOAD CASE PIER 1 ULTIMATE COMBO 1
1 1.2 87 1.5 6 1.7 27 1.7 49 1.7 69 1.7
LOAD COMB 88 COMBINATION LOAD CASE PIER 1 ULTIMATE COMBO 3
1 1.2 87 1.5 2 0.45 3 0.45 6 1.5 27 1.5 49 1.5 69 1.5
LOAD COMB 89 COMBINATION LOAD CASE PIER 1 COMBO 4
1 1.2 87 1.5 2 1.4 3 1.4
LOAD COMB 90 COMBINATION LOAD CASE PIER 10 ULTIMATE COMBO 1
1 1.2 87 1.5 16 1.7 35 1.7 56 1.7 76 1.7
LOAD COMB 91 COMBINATION LOAD CASE PIER 10 ULTIMATE COMBO 3
84
1 1.2 87 1.5 2 0.45 3 0.45 15 1.7 35 1.7 55 1.7 75 1.7
LOAD COMB 92 COMBINATION LOAD CASE PIER 10 ULTIMATE COMBO 4
1 1.2 87 1.5 2 1.4 3 1.4
PERFORM ANALYSIS PRINT ALL
DEFINE ENVELOPE
86 88 89 ENVELOPE 1 TYPE STRENGTH
90 TO 92 ENVELOPE 2 TYPE STRENGTH
END DEFINE ENVELOPE
LOAD LIST ENV 2
START CONCRETE DESIGN
CODE CANADIAN
CLB 0.04 MEMB 8
DESIGN COLUMN 8
MINSEC 10 MEMB 11
DESIGN COLUMN 11
END CONCRETE DESIGN
FINISH
85
Appendix 6 STAAD Pro input for projected climate
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 23-Jan-17
END JOB INFORMATION
INPUT WIDTH 79
UNIT METER KN
JOINT COORDINATES
2 0 5 0; 4 13.2 5 0; 5 14.2 5 0; 6 -1 5 0; 8 0 5 20; 10 13.2 5 20;
11 14.2 5 20; 12 -1 5 20; 14 0 5 40; 16 13.2 5 40; 17 14.2 5 40; 18 -1 5 40;
20 0 5 60; 22 13.2 5 60; 23 14.2 5 60; 24 -1 5 60; 26 0 5 80; 28 13.2 5 80;
29 14.2 5 80; 30 -1 5 80; 32 0 5 100; 34 13.2 5 100; 35 14.2 5 100;
36 -1 5 100; 37 1.65 5 0; 38 1.65 5 20; 39 1.65 5 40; 40 1.65 5 60;
41 1.65 5 80; 42 1.65 5 100; 43 3.3 5 0; 44 3.3 5 20; 45 3.3 5 40; 46 3.3 5 60;
47 3.3 5 80; 48 3.3 5 100; 49 4.95 5 0; 50 4.95 5 20; 51 4.95 5 40;
52 4.95 5 60; 53 4.95 5 80; 54 4.95 5 100; 55 6.6 5 0; 56 6.6 5 20;
57 6.6 5 40; 58 6.6 5 60; 59 6.6 5 80; 60 6.6 5 100; 61 8.25 5 0; 62 8.25 5 20;
63 8.25 5 40; 64 8.25 5 60; 65 8.25 5 80; 66 8.25 5 100; 67 9.9 5 0;
68 9.9 5 20; 69 9.9 5 40; 70 9.9 5 60; 71 9.9 5 80; 72 9.9 5 100; 73 11.55 5 0;
74 11.55 5 20; 75 11.55 5 40; 76 11.55 5 60; 77 11.55 5 80; 78 11.55 5 100;
79 0 5 120; 80 13.2 5 120; 81 14.2 5 120; 82 -1 5 120; 83 1.65 5 120;
84 3.3 5 120; 85 4.95 5 120; 86 6.6 5 120; 87 8.25 5 120; 88 9.9 5 120;
89 11.55 5 120; 90 0 5 -20; 91 13.2 5 -20; 92 14.2 5 -20; 93 -1 5 -20;
94 1.65 5 -20; 95 3.3 5 -20; 96 4.95 5 -20; 97 6.6 5 -20; 98 8.25 5 -20;
99 9.9 5 -20; 100 11.55 5 -20; 109 0 5 -40; 110 13.2 5 -40; 111 14.2 5 -40;
112 -1 5 -40; 113 1.65 5 -40; 114 3.3 5 -40; 115 4.95 5 -40; 116 6.6 5 -40;
117 8.25 5 -40; 118 9.9 5 -40; 119 11.55 5 -40; 120 0 -9.78 100;
121 13.2 -9.78 100; 122 0 -9.78 -20; 123 13.2 -9.78 -20; 124 0 -9.78 0;
125 13.2 -9.78 0; 126 0 -9.78 80; 127 13.2 -9.78 80; 128 0 -9.78 20;
129 13.2 -9.78 20; 130 0 -9.78 60; 131 13.2 -9.78 60; 132 0 -9.78 40;
133 13.2 -9.78 40;
86
MEMBER INCIDENCES
1 93 90; 2 6 2; 3 12 8; 4 18 14; 5 24 20; 6 30 26; 7 36 32; 8 90 122; 9 2 124;
10 8 128; 11 14 132; 12 20 130; 13 26 126; 14 32 120; 15 90 109; 16 2 90;
17 8 2; 18 14 8; 19 20 14; 20 26 20; 21 32 26; 22 79 32; 23 90 94; 24 2 37;
25 8 38; 26 14 39; 27 20 40; 28 26 41; 29 32 42; 30 94 113; 31 37 94; 32 38 37;
33 39 38; 34 40 39; 35 41 40; 36 42 41; 37 83 42; 38 94 95; 39 37 43; 40 38 44;
41 39 45; 42 40 46; 43 41 47; 44 42 48; 45 95 114; 46 43 95; 47 44 43;
48 45 44; 49 46 45; 50 47 46; 51 48 47; 52 84 48; 53 95 96; 54 43 49; 55 44 50;
56 45 51; 57 46 52; 58 47 53; 59 48 54; 60 96 115; 61 49 96; 62 50 49;
63 51 50; 64 52 51; 65 53 52; 66 54 53; 67 85 54; 68 96 97; 69 49 55; 70 50 56;
71 51 57; 72 52 58; 73 53 59; 74 54 60; 82 97 116; 83 55 97; 84 56 55;
85 57 56; 86 58 57; 87 59 58; 88 60 59; 89 86 60; 90 97 98; 91 55 61; 92 56 62;
93 57 63; 94 58 64; 95 59 65; 96 60 66; 97 98 117; 98 61 98; 99 62 61;
100 63 62; 101 64 63; 102 65 64; 103 66 65; 104 87 66; 105 98 99; 106 61 67;
107 62 68; 108 63 69; 109 64 70; 110 65 71; 111 66 72; 112 99 118; 113 67 99;
114 68 67; 115 69 68; 116 70 69; 117 71 70; 118 72 71; 119 88 72; 120 99 100;
121 67 73; 122 68 74; 123 69 75; 124 70 76; 125 71 77; 126 72 78; 127 100 119;
128 73 100; 129 74 73; 130 75 74; 131 76 75; 132 77 76; 133 78 77; 134 89 78;
135 100 91; 136 73 4; 137 74 10; 138 75 16; 139 76 22; 140 77 28; 141 78 34;
142 91 123; 143 4 125; 144 10 129; 145 16 133; 146 22 131; 147 28 127;
148 34 121; 149 91 110; 171 4 91; 172 10 4; 173 16 10; 174 22 16; 175 28 22;
176 34 28; 177 80 34; 178 91 92; 179 4 5; 180 10 11; 181 16 17; 182 22 23;
183 28 29; 184 34 35;
ELEMENT INCIDENCES SHELL
150 82 81 35 36; 151 36 35 29 30; 152 30 29 23 24; 153 24 23 17 18;
154 18 17 11 12; 155 12 11 5 6; 156 6 5 92 93; 187 93 92 111 112;
DEFINE PMEMBER
1 23 38 53 68 90 105 120 135 178 PMEMBER 1
4 26 41 56 71 93 108 123 138 181 PMEMBER 2
3 25 40 55 70 92 107 122 137 180 PMEMBER 3
ELEMENT PROPERTY
87
150 TO 156 187 THICKNESS 0.35
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 2.17185e+007
POISSON 0.17
DENSITY 23.5616
ALPHA 1e-005
DAMP 0.05
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
15 TO 22 30 TO 37 45 TO 52 60 TO 67 82 TO 89 97 TO 104 112 TO 119 127 TO 134 -
149 171 TO 177 PRIS YD 1 ZD 0.6 YB 0.75 ZB 0.25
1 TO 7 23 TO 29 38 TO 44 53 TO 59 68 TO 74 90 TO 96 105 TO 111 120 TO 126 -
135 TO 141 178 TO 184 PRIS YD 1 ZD 0.8
8 TO 14 142 TO 148 PRIS YD 0.8
CONSTANTS
BETA 180 MEMB 15 TO 22 30 TO 37 45 TO 52 60 TO 67 82 TO 89 97 TO 104 -
112 TO 119 127 TO 134 149 171 TO 177
MATERIAL CONCRETE ALL
SUPPORTS
79 TO 89 109 TO 119 PINNED
120 TO 133 FIXED
DEFINE MOVING LOAD
TYPE 1 LOAD 25 62.5 62.5 87.5 75
DIST 3.6 1.2 6.6 6.6 WID 1.8
TYPE 2 LOAD 25 62.5 62.5 87.5 75
DIST 3.6 1.2 6.6 6.6 WID 1.8
TYPE 3 LOAD 25 62.5 62.5 87.5 75
DIST 3.6 1.2 6.6 6.6 WID 1.8
TYPE 4 LOAD 25 62.5 62.5 87.5 75
DIST 3.6 1.2 6.6 6.6 WID 1.8
88
LOAD 1 LOADTYPE Dead TITLE SELF WEIGHT
SELFWEIGHT Y -1
LOAD 2 LOADTYPE Dead TITLE VERTICAL WIND
ELEMENT LOAD
150 TO 156 187 PR GY -1.38
LOAD 3 LOADTYPE Dead TITLE HORIZONTAL WIND
MEMBER LOAD
8 TO 10 12 TO 14 142 TO 148 UNI GX -50 0 2.26
LOAD 5 LOADTYPE Dead TITLE HYDRODYNAMIC LOAD
MEMBER LOAD
8 TO 14 142 TO 148 UNI GX -4.3 2.26 14.78
LOAD GENERATION 20
TYPE 1 1.2 5 -40 ZINC 8
LOAD GENERATION 20
TYPE 2 4.2 5 -40 ZINC 8
LOAD GENERATION 20
TYPE 3 7.2 5 -40 ZINC 8
LOAD GENERATION 20
TYPE 4 10.2 5 -40 ZINC 8
LOAD 87 LOADTYPE Dead TITLE WEARING SURFACE
ELEMENT LOAD
150 TO 156 187 PR GY -0.01
LOAD COMB 4 COMBINATION LOAD CASE 4
1 1.2 5 1.3
LOAD COMB 86 COMBINATION LOAD CASE PIER 1 ULTIMATE COMBO 1
1 1.2 87 1.5 6 1.7 27 1.7 49 1.7 69 1.7
LOAD COMB 88 COMBINATION LOAD CASE PIER 1 ULTIMATE COMBO 3
1 1.2 87 1.5 2 0.45 3 0.45 6 1.5 27 1.5 49 1.5 69 1.5
LOAD COMB 89 COMBINATION LOAD CASE PIER 1 COMBO 4
1 1.2 87 1.5 2 1.4 3 1.4
LOAD COMB 90 COMBINATION LOAD CASE PIER 10 ULTIMATE COMBO 1
89
1 1.2 87 1.5 16 1.7 35 1.7 56 1.7 76 1.7
LOAD COMB 91 COMBINATION LOAD CASE PIER 10 ULTIMATE COMBO 3
1 1.2 87 1.5 2 0.45 3 0.45 15 1.7 35 1.7 55 1.7 75 1.7
LOAD COMB 92 COMBINATION LOAD CASE PIER 10 ULTIMATE COMBO 4
1 1.2 87 1.5 2 1.4 3 1.4
PERFORM ANALYSIS PRINT ALL
DEFINE ENVELOPE
86 88 89 ENVELOPE 1 TYPE STRENGTH
90 TO 92 ENVELOPE 2 TYPE STRENGTH
END DEFINE ENVELOPE
LOAD LIST ENV 2
START CONCRETE DESIGN
CODE CANADIAN
CLB 0.04 MEMB 8
DESIGN COLUMN 8
MINSEC 10 MEMB 11
DESIGN COLUMN 11
END CONCRETE DESIGN
FINISH
90
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